Compatible with both compact and full-size main batteries, the Eagle Powertrain Range Extender is the perfect solution for when longer adventures call for additional range. Designed to work with the robust and secure Powertrain Cage, it allows riders to use a standard water bottle on most rides, but easily swap in the 252-watt Eagle Powertrain Range Extender to gain up to 40% more riding time. As an added plus, the Powertrain Cage can be oriented for right or left-hand use. For riders who prefer to run a compact main battery most of the time, the Eagle Powertrain Range Extender is the answer when plans call for bigger outings.FEATURES* Attaches via Powertrain Cage, left or right mount, fits a standard water bottle.* Gives 250 watts and up to 40% more riding time.* Compatible with full size and compact main batteries.* SRAM Model ID: BT-ETP-RE-A1