Derailleurs

The Box Four Rear Derailleur is the base of Prime 9 Technology that offers an affordable clutch based 1 by 8-speed derailleur that is simple and light; this makes it a perfect candidate for every entry-level bike that traditionally has a 3 by drive-train that is neither durable nor user friendly.

SRAM's low-profile GX 2x10 Front Derailleur was designed specifically around SRAM X-GLIDE shifting. This stiff, strong front derailleur provides, crisp, precise action for fast, smooth and reliable shifting season in and season out.

SRAM's low-profile GX 2x10 Front Derailleur was designed specifically around SRAM X-GLIDE shifting. This stiff, strong front derailleur provides, crisp, precise action for fast, smooth and reliable shifting season in and season out.

Shimano's unbelievable Di2 technology has made the leap to the trails with their XTR Di2 drivetrain. This rear derailleur features all of the race-day performance you've come to expect from XTR, and the unrivaled stability, speed, and performance of an electronic drivetrain. Since there aren't any cables to stretch or housing to create friction, shift performance stays amazingly perfect, delivering flawless shifts any time, under any condition. System communication with the front derailleur eliminates chain rub and, if you prefer, the rear derailleur can be optimized to use Shimano's Synchronized Shift technology.

Altus wide link 7/8-speed compatible dual-pull multi-fit front derailleur for recreational off-road use. - Compact conventional swing design - Low-friction wide linkage reduces shifting effort and increases rigidity - Dual-pull design allows it to be used with top or bottom cable routing - Multi clamp band is compatible with all frame dimensions - 66-69 degree chainstay to seat tube angle range - For outer chainring size from 42 to 48 tooth, total capacity 20 teeth - Compatible with 7- or 8-speed drivetrains

Shimano's 105 Braze-On Front Derailleur sports a cold forged-aluminum body with Shimano's extra wide-pivot design for lightning-quick and super-smooth shifts. The steel cage ensures excellent durability.

Shimano Ultegra R8000 front derailleur. - Lighter front shifting operation - Link construction matches the force curve of the hand more naturally to reduce effort at the end of shifting - 100% perfect setting - New link construction allows for more flexible cable routing design - TL-FD68 and turning converter is not required in assembly - Easy and precise setting - Now possible to adjust cable tension on FD without specialized tools - Redesigned to fit wider gear pitch without sacrificing shifting performance - Shorter length of rear center (410mm) with O.L.D. 135mm - Model Number: FD-R8000-B - Series: Ultegra - Top Gear Teeth: 46-53T - Chain Stay Angle: 61-66 - Chain Line: 43.5 - Average Weight: 106 grams

The Shimano Altus RD-M310 rear derailleur is a quality, durable replacement rear derailleur for 7 and 8-speed drivetrains. - 13t upper and 15t lower pulleys - Maximum cog size: 34t - Total capacity: 43t

R10 front derailleurs work with 10-speed Shimano-compatible road shifters. Designed to work with a variety of chainring combinations, these workhorse components will get you rolling again. - Cold-forged aluminum body

R-series rear derailleurs are designed to work with Shimano-compatible road shifters. These R9 rear derailleurs combine compatibility, weight savings, and a robust design. - Weight-saving aluminum bracket body and outer link - Steel pulley cage for extra chain-rub durability - Compatible with Shimano 9 and 10-speed road systems - Not compatible with Shimano Tiagra 4700 road system - Short cage for double crankset 28T max cog setup - Medium cage for double crankset and 34T max cog - Long cage for triple crankset and 28T max cog

The 7-speed X-HORIZON rear derailleur makes shifting smooth and reliable no matter where you ride. Engineered to maintain consistent chain gap across all seven gears, X-HORIZON eliminates vertical movement for faster shifting, reduced shift force, and an end to ghost shifting. Our new, Type-3 roller bearing clutch features a smoother torque curve for a quieter, more consistent operation and feel. The 12-tooth X-SYNC pulley wheel holds the chain in place, reducing bounce and chain slap. Additionally, CAGE LOCK technology makes wheel removal and installation easier than ever. Paired with the X01 DH 7-speed shifter, X-HORIZON forms the backbone of X-ACTUATION technology—and that means completely smooth shifting action. - Updated design of the rear derailleur incorporates our proven X-HORIZON design and new Type-3 roller bearing clutch technology - 12-tooth X-SYNC pulley wheels - Large upper pulley offset automatically adjusts chain gap - Sealed cartridge bearings

Shimano's 105 Rear Derailleur delivers high-end function with upscale looks. With a body of light, durable cold-forged aluminum in Shimano's wide-pivot design with their light-action spring, rear shifting is practically effortless and always super smooth. The top pulley stays a uniform distance from each cassette cog ensuring that every shift resonates with the plunk of exact gear engagement.

Elevating the shift, expanding the capable, the X01 Eagle derailleur features an updated cage architecture to provide better chain management than ever. The X01 Eagle rear derailleur works with the new 10-52T cassettes and is backward-compatible with 10-50T options, as well. - Updated cage provides better chain retention and more precise shifts - Backward-compatible design works with 10-50T and 10-52T cassettes

M21 rear derailleurs are designed to work with 6- and 7-speed Shimano road and mountain shifters. Enjoy the wide variety of bikes you can get going again with M21 rear derailleurs. - Robust composite and steel construction - Compatible with Shimano 6- and 7-speed mountain and road systems

If your ride doesn't feel complete until you get a little dirt on your tires, you know the importance of capable components that can tackle anything. The Force XPLR eTap AXS rear derailleur is a dedicated 1x-specific unit designed for use with the XPLR 10-44 cassette. It makes for an uncluttered drivetrain that takes on pavement and singletrack with equal aplomb. Wireless and proven eTap shift logic, AXS connectivity, and advanced chain management mean this derailleur does exactly what you want when you need it. NOTE: Does not include eTap battery or charger. Compatible with existing eTap batteries. - Wireless electronic eTap shift logic for intuitive shifting, easy setup, and reliability - 1x specific for use with 10-44T XPLR and 10-36T cassettes - SRAM AXS enabled, allowing easy personalization - Chain management keeps the drivetrain quiet and secure - Large X-SYNC pulleys for increased durability and efficiency - Cage Material (RD): Aluminum - Pulley Bearings Material: Steel - Max Tooth: 44 NOTE: Does not include eTap battery. Compatible with existing eTap batteries.

Optimized for Shimano compatible 9-speed road drivetrains, R9 front derailleurs feature metal construction and rapid shifting response. - Cold-forged aluminum body

• 11-speed DynaSys compatible • Light Shift Operation With 20% Less Effort • Improved chain stability • Efficient Shifting And Smoother Driving • New Shadow Design With Optimized Slant Angle • New Shift Cable With New Hyper Low-Friction Coating Technology • New Shadow Design With Optimized Slant Angle For Stable Gear Position • Easy-To-Adjust Chain Stabilizer • Efficient Pulley Teeth Design • Direct Mount compatible

SRAM's X5 10-Speed Rear Derailleur provides precise, dependable shifting along with long-term durability. Its aluminum construction keeps the weight down, while SRAM's 1:1 actuation ratio and direct cable routing provide quick, reliable shifts.

The Campagnolo EKAR Rear Derailleur is designed for the 1x13-speed EKARndrivetrain with a gravel-orientated performance & build. - 2D parallelogram trajectory offers precise mechanical movement for 13 sprockets - High grade polymer pulley wheels (12T upper, 14T lower) allow for smooth chain running and secure retention - Carbon fiber-reinforced polyamide and anodized 7075 and 6082 alloys are lightweight, strong, and durable - Stainless steel bolts for strength and long-term resilience on gravel - Includes clutch lock for easy wheel removal Specifications: - Largest Cog: 44 - Rear Derailleur Mount Type: 10x1 Standard - Chain Wrap Capacity (teeth): 34 - Cage Length: Medium - Rear Der/Shifter Compatibility: Campy EKAR - Drivetrain Speeds: 13 - Weight: 275g

- Model Number: FD-R3000 - Series: SORA - Top Gear Teeth: 46-52T - Chain Stay Angle: 61-66 - Chain Line: 43.5 - Models: Braze-on and band clamp available - Band clamp model includes shims for 31.8/28.6mm seat tubes

The Shimano FD-R7000 11-speed front derailleur offers lighter front shifting with a natural stroke feel. The derailleur's cage design is optimized to perform with disc brake road bikes, while multiple cable routing options and integrated cable tension adjustment allow for precise setup and easy adjustments. As part of Shimano's 105 R7000 series, this front derailleur is ideal for beginner road cyclists, combining great value with trickle-down technology from Shimano's top-tier groups. - Cage is optimized for disc brake road bikes - Integrated cable tension adjustment for precise and easy adjustments - More frame cable routing options

Shimano's Deore Shadow+ Rear Derailleur is loaded with mountain bike technology. The Shadow design tucks the rear derailleur closer in to the wheel, reducing damage from rocks, roots, and trail obstacles. When it comes to gear changes, Shimano's Dyna-Sys supplies consistent, smooth shifting across the entire cassette. And the Shadow+ clutch maximizes chain control by virtually eliminating chain slap and excess noise with its integrated cage-tensioning clutch. - Medium Cage (for 2x10 drivetrains) - Long Cage (for 3x10 drivetrains) - For use with Shimano 10-speed drivetrains - High-efficiency drivetrain for aggressive trail riding - Optimized gear combinations and ratios for trail riding - Maximum chain wrap capacity: 41T (medium cage)/43T (long cage) - Largest cog: 42T (medium cage)/36T (long cage) - Compatible with wide range cassette - Silent and stable for technical trail riding - Improved stability and chain retention longevity - Light shifting effort - OPTISLICK cable - Smooth and precise shifting - DYNA-SYS compatible system

Claris R2000 series offers reliable functionality at a price point for new riders. Designed for easy rides around town with the durability to handle a long tour, Claris R2000 has a sporty design and promises the opportunity of comfortable and casual riding.

SRAM's X01 Rear Derailleur packs a massive amount of technology into its compact, lightweight body. This 11-speed gear changer uses a “horizontal parallelogram” design that limits all movement to the horizontal axis, reducing the force it takes to shift. The Type 2 clutch is brilliant. This self-lubricating, one-way roller clutch controls your chain tension to eliminate chain slap and give you smooth, consistent shifts over any terrain. For quicker, smoother, more exact shifting, the large upper pulley's offset design maintains a consistent chain gap across all gears.

XLE Rear Derailleur for 10-speed Shimano drivetrains - For MEGA Sprockets w/large cog size 36-42T - Compatible with single, double, or triple cranksets - Total Capacity: 47T

SRAM's X3 Rear Derailleur is ready for adventure. Its composite and steel construction is tough, while SRAM's 1:1 actuation ratio and direct cable routing provide quick, reliable shifts. This derailleur is compatible with 7- or 8-speed drivetrains.

The Box One Prime 9 Rear Derailleur takes the advantages of our legacy 9-speed drive-train but adds the advancements of a modern 1 by; a fully adjustable Tri-Pack Clutch, and an x-wide cage optimized for an 11-50T cassette. Forged construction steps up the durability and performance to an unparalleled level. Suited for the most demanding terrain.

SRAM's X5 9-Speed Rear Derailleur provides precise, dependable shifting along with long-term durability. Its aluminum construction keeps the weight down, while SRAM's 1:1 actuation ratio and direct cable routing provide quick, reliable shifts.

This new NX Eagle derailleur features the proven SRAM 1x-specific X-HORIZON design. The larger, 14-tooth X-SYNC lower pulley easily facilitates 11- to 50- and 10- to 50-tooth cassette capacity, and also adds to NX Eagle's overall smooth-pedaling feel. The Type-3 ROLLER BEARING CLUTCH provides quiet, consistent performance and durability. - Eagle technology provides an expanded, optimum, gear range making you fast on the flats, giving you control on the climbs and unleashing your speed on the descents - Eagle is a complete drivetrain system that was developed to be an integrated high-performance ecosystem. The engineering and testing that went into the development provide for maximum performance, safety, and long-term durability to ensure a great consumer ride experience. We guarantee this performance when Eagle drivetrains are used as a complete ecosystem. For additional information, please contact your SRAM Sales Contact. - Completely new rear derailleur incorporating our proven X-HORIZON design and new Type-3 ROLLER BEARING CLUTCH technology - Eagle ecosystem-engineered mounting system and CAGE LOCK positioning add robustness - Eagle pulley technology provides greater efficiency, crisper shifting and quieter operation - Speed (RD): 12s - Cable pull ratio: X-actuation - Cage (RD): Long - Max tooth: 50 - Color (RD): Black - Pulley bearings material: Steel - Cage material (RD): Steel

It's an all-new derailleur that's specifically designed and optimized to be motor-driven instead of cable-actuated. AXS powered components enable customization and scale to an individual rider's liking via the AXS App. It features a shorter cage for 10mm more ground clearance, with more chain wrap on the cassette to sit slightly further forward, and further inboard from mechanical Eagle. The Eagle AXS derailleur is smart enough to protect itself thanks to its incredibly resilient Overload Clutch. In the event of an impact, the motor gearbox disengages, giving the derailleur freedom to move, and instantly returns back to its position for a seamless experience for the rider. The system is tested to IP69K water and dust proofing standard for creek crossings, mud splatterings and the resulting post-ride pressure washings. - Enduro focus and trail ready - Forged aluminum cage - Stainless hardware - Black/Polar colorways - Eagle technology - Overload Clutch protection - AXS enabled componentry software that makes it possible to both program and personalize new SRAM and RockShox components - System is completely water and dust proof to IP69K - Eagle AXS is designed to work with X-DOME Eagle cassettes only, providing the most precise, silent, and reliable shift performance available.

The SRAM Force eTap AXS front derailleur is AXS enabled for easy personalization. The redesigned derailleur offers better rear-tire clearance—for those that explore all roads—and works perfectly with all chainring combinations. No compromises; never miss a shift. - AXS enabled for easy personalization - Elegant and streamlined form for more rear-tire clearance - SRAM Yaw trimless cage technology with an optimized cage profile for new chainring combinations - Compatible with existing eTap batteries

Shimano's groundbreaking 6800-series front derailleur delivers a shorter stroke at the lever and substantially lighter action for lightning fast shifts with just a flick of your finger. The redesigned pull arm offers more direct tactile feedback during shifts. The derailleur support bolt creates more solid contact to the frame, stiffening the derailleur and stabilizing it for faster, smoother shifts.

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience while delivering shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features an ON/OFF switch for the chain stabilizer. The RD-RX810 rear derailleur is compatible with road cassettes with a max cog size of 34T. - Adjustable, gravel-tuned chain stabilizer prevents chain slapping and drops - Switch stabilizer ON/OFF to match the terrain - Silent and uninterrupted rear shifting on rough terrain - Low cog: Max. 34T/Min. 30T - High cog: Max. 11T/Min. 11T - Total capacity: 40T - Compatible with current road Dual Control Lever - Maximum front chainring range: 17T

SRAM's X9 Front Derailleur sports a forged-aluminum cage and a cutout design for exceptional durability with minimal weight. It provides, crisp, precise action for fast, smooth and reliable shifting season in and season out.

Shimano 105 7000-series components offer much of the same technology and functionality as their top-level 11-speed drivetrains at a more budget-friendly price point. The RD-R7000 rear derailleur provides stable shifting performance and wide-range compatibility in two different cage lengths. The Shadow RD design limits the amount the derailleur sticks out from the side of the bike, reducing the risk of it making contact with objects and bending. - Maximum cog size: 30t (SS) / 34t (GS) - Total capacity: 35t (SS) / 39t (GS) - Pulleys: 11t - Chain compatibility: HG-EV 11-speed/HG-X11 - Direct mount compatible

Designed with the rider in mind, the ADVENT rear derailleur packs trail-ready features into an attainable wide-range drivetrain system. The derailleur kinematics are precisely tuned to use a more direct cable path, making the shifting feel consistent across the lowest and highest gears, and everything in between. - Clutch provides stronger chain management over rough terrain - Ratchet-and-pawl clutch is easily adjustable and repairable - Direct cable routing for smooth, responsive shifting - Compatible with 11-42T 9-speed cassettes - Compatible with ADVENT shifters only

Riders want the derailleur to do its job shifting on command, whether under climbing load or the stage finish. The GX Eagle derailleur gets it done with an updated cage architecture that improves chain management. Refined to work with the new 10-52T cassettes, it's also backward-compatible with 10-50T cassettes for greater versatility and incremental upgrade. It's finished with the new GX Eagle master colorway to complement any cassette and chain colorway a rider wants from the Eagle Colorsystem. - Backward-compatible—works with both 10-50T and newer 10-52T cassettes - Updated cage architecture provides better chain retention and precise shifts

- Model Number: RD-R3000-GS - Series: SORA - Maximum Sprocket: 34T - Minimum Sprocket: 11T - Maximum Front Difference: 20T - Total Capacity: 43T

Enjoy quality and reliability with the Shimano Tourney 6/7-speed rear derailleur. It makes use of Shimano SIS, HyperGlide, and Double Servo technologies for smooth, accurate shifts. - Maximum cog size: 34t - Total capacity: 43t

Shimano's Deore XT Rear Derailleur uses cold-forged construction and cutting edge technology to deliver crisp shifting, real-world reliability, and trademark precision. Plus-type derailleurs use a lever-actuated clutch spring to prevent chain slap, reduce noise while on the trail, and improve chain engagement when riding over rough terrain. Sealed pulley bearings keep things spinning smoothly, and wide plate construction prevents the derailleur from getting clogged with mud and debris.

- 2:1 actuation ratio compatible with most Shimano 3x9sp drivetrains - Aluminum and steel construction with 11-tooth pulleys barrel adjuster

Centos front derailleurs are precisely manufactured for responsive, accurate shifting under race conditions. - Compatible with Shimano Tiagra 4700 10-speed road systems - Includes adapter for 31.8 and 28.6mm seat tubes

- 11-34T - Weight—354g

- Model Number: FD-R3030 - Series: SORA - Top Gear Teeth: 50T - Chain Stay Angle: 63-66 - Chain Line: 45 - Models: Braze-on and band clamp available - Band clamp model includes shims for 31.8/28.6mm seat tubes

Combining Shimano's Di2 platform and the road incarnation of Hyperglide+, the Ultegra FD-R8150 front derailleur shifts between chainrings with the fast and seamless action. - Small, sleek and lightweight front derailleur - Frontal area is smaller than previous designs to reduce aerodynamic drag - Top gear teeth capacity: 50-54t - 61-66 degree chainstay angle - Includes 1 SD300 port

The Shimano Dura-Ace RD-R9250 rear derailleur integrates the system charging port and a wireless connectivity unit all while delivering super fast, precise shifting worth of any podium. A single cage length shifts cassettes from 11-28 to 11-34, offering exceptional versatility. - Ultra-fast rear Di2 shifting - Compact design includes an integrated wireless unit, charger, switch - Wider range capacity - Max. low sprocket: 34T - CFRP rear derailleur plate - LED status indicator - Battery indicator, pairing, adjust mode etc.

More than a mechanical derailleur with a battery and a motor bolted on, the Eagle AXS derailleur is the heart of the whole AXS system. It features a shorter cage for 10mm more ground clearance, with more chain wrap on the cassette to sit slightly further forward, and further inboard from mechanical Eagle. Instantaneous shifts from a single touch even while under World Cup-winning chain loads recorded in the heat of racing and affirmed in the test lab. Tested to IP69K water and dust proofing standard so whatever race day brings, you’re ready. - XC focus and trail ready - Carbon cage - Ti hardware - Rainbow colorway - Eagle technology - Overload Clutch protection - AXS enabled componentry software that makes it possible to both program and personalize new SRAM and RockShox components - System is completely water and dust proof to IP69K - Eagle AXS is designed to work with X-DOME Eagle cassettes only, providing the most precise, silent, and reliable shift performance available. - Battery sold separately

M-series rear derailleurs are designed to work with 7, 8, and 9-speed Shimano-compatible mountain and road shifters. These legendary M26 rear derailleurs put cyclists of all ages back on their saddles with as little frustration as possible. - Robust composite and steel construction - Compatible with Shimano 7, 8, and 9-speed mountain and road systems

- Compatible with all Shimano 9-speed HG cassettes, 9-speed mountain shifters, and 9-speed chains - Fluorine coated link pin bushings - On and Off-Road compatible with 28 – 34T low cassette sprocket

Dimension Chainstay Mount Single-Speed Tensioners - Fits stays with diameters from 19.8-22.2mm - 74g

FD-A073 Tourney Front Derailleur for 2x7 or 3x7 drivetrains. - SG-X chainring compatible - Quick assembly - Interchangeable with SHIMANO road 7-speed system - Easy adjusting - Light operation and smooth shifting

Occupying a new realm in shifting performance, the redesigned XX1 Eagle derailleur gives no-compromise racers and dream-bike builders a true top-tier option. The crisp, precise XX1 shifting feel athletes rely on now features an updated cage geometry for improved chain management. Occupying its rightful place at the top of the Eagle ecosystem, the XX1 Eagle rear derailleur makes full use of the new 10-52T cassettes and is backward-compatible with 10-50T cassettes, as well. - Updated cage geometry provides better chain retention and crisper shifting - Comes in XX1 Eagle master colorway as part of Eagle Colorsystem to go with all cassette and chain color options - Backward-compatible with 10-50T cassettes, works with new 10-52T cassettes

Shimano Ultegra Di2 Shadow rear derailleur. - Sleek integrated appearance - New low-profile design - Shimano Shadow RD - Race endurance - Optimized slant angle - Maintain race concentration with more intuitive shift control - System communication with front derailleur - Shimano Synchronized Shift - Wide compatibility - Short cage covers: 11-25T to 11-30T - Medium cage covers: 11-28T to 11-34T - Average Weight: 242 grams (SS type), 249 grams (GS type)

- Prevents chain derailment when shifting to inner ring - Adjustable hose-type clamp fits 1-1/8" to 1-3/8" seat tubes

Despite its smaller, lighter design, the Shimano Dura-Ace FD-R9250 offers ultra-fast front shifting. - Fast Di2 shifting performance - Smaller, sleeker, lighter - Frontal area is smaller than previous designs to reduce aerodynamic drag - Top gear teeth capacity: 50-55t - 61-66 degree chainstay angle - Includes 1 SD300 port

The SRAM RED eTap AXS front derailleur leverages our advancements with X-Range gearing. The derailleur design carves out space for wide rear-tire clearance, making it a perfect fit for modern riding. And the shifting is quick and precise. - AXS enabled for easy personalization - Elegant and streamlined form for more rear-tire clearance - SRAM Yaw trimless cage technology with an optimized cage profile for new SRAM RED front chainring combinations - The most responsive, quick, and precise front shifting to date - Compatible with existing eTap batteries - Speeds: 2x12 - Front derailleur compatibility: Road-Yaw - Chainstay Angle: 61-66 degrees NOTE: Does not include eTap battery. Compatible with existing eTap batteries.

The Shimano Altus rear derailleur brings Shadow technology and wide-range capability to 9-speed drivetrains - B tension spring for quick and easy wheel installation and removal - Super low-profile concept with SHADOW mechanism - Wider linkage ensures durability and more precise shifting - Easy adjustment and maintenance - Direct mount compatible - Maximum cog size: 36t - Total capacity: 45t

Compatible with DUAL SIS index shifting, the Shimano Tourney TY front derailleur is perfect for 3x7 and 3x6 speed drivetrains. - Action: TOP SWING - Angled clamp band design - Applicable Top-Mid tooth difference: 8T - Chain line: 47.5/50mm - Chain stay angle: 66-69 - Top gear teeth: 42T - Total capacity: 18T

SRAM's GX 2x10 rear derailleur provides incredible shifting speed and precision. Exact Actuation technology eliminates slop and shifting variation. Roller Bearing Clutch technology delivers maximum drivetrain stability—even through the most punishing terrain. And with Cage Lock technology, wheel removal and installation are easier than ever.

If your ride doesn't feel complete until you get a little dirt on your tires, you know the importance of capable components that can tackle anything. The Rival XPLR eTap AXS rear derailleur is a dedicated 1x-specific unit designed for use with the XPLR 10-44 cassette. It makes for an uncluttered drivetrain that takes on pavement and singletrack with equal aplomb. Wireless and proven eTap shift logic, AXS connectivity and advanced chain management mean this derailleur does exactly what you want when you need it. - Wireless electronic eTap shift logic for intuitive shifting, easy setup, and reliability - 1x specific for use with 10-44T XPLR and 10-36T cassettes - SRAM AXS enabled, allowing easy personalization - Chain management keeps the drivetrain quiet and secure - Large X-SYNC pulleys for increased durability and efficiency - Compatible with existing eTap batteries - Cage Material (RD): Aluminum - Pulley Bearings Material: Steel - Max Tooth: 44 NOTE: Does not include eTap battery. Compatible with existing eTap batteries.