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.Key Features:Attaches 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