Sram: Compatible with both compact and full-size main batteries, the Eagle Powertrain Range Extender is the perfect solution for additional 250Wh and up to 40% more riding time. Designed to work with the robust and secure Powertrain mounting system, it allows riders to switch between the Range extender and a cage for standard water bottles. 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. The range extender is compatible with the Eagle Powertrain system. Please confirm with your frame manufacturer for compatibility on your bike. FEATURESAttaches via Eagle Powertrain mounting system.Fits a standard water bottle.Gives 250 watts and up to 40% more riding time.Compatible with full size and compact main batteries.Does not fit Nukeproof Megawatt Carbon SPECIFICATIONSCharge time 2hrsBattery size 250WhCell type 18650Voltage 36 volt