The SRAM AXS eTap Battery provides extra juice for your eTap derailleurs. This rechargeable battery is a great addition to your eTap drivetrain, giving you 600 miles of riding per charge. It's interchangeable between front and rear derailleurs for maximum convenience. For use with SRAM eTap and eTap AXS drivetrains Replacement battery for front or rear derailleur or Reverb dropper posts Includes battery terminal cover
These batteries are specific to the SRAM wireless eTap derailleur system. Replacement batteries can be ride saving on long rides in case installed batteries lose the charge.