converts 27.5 mountian bike to an Ebike 1500 watts max output, 54 v battery and charger, also brake levers so you can choose between that or the brake sensor. you will need a cassete, what matches your bikes rear gears (mine is 7 speeds rear starting $25) BIKE MUST BE 27 1/2" with disc breaks and rear dropout of 132 to 138 mm. top speed 38 mph you will need to add a torque arm for safety and prevent damage. works but my bike has too narrow a rear drop out. Spent way more than what im asking