Function: high, medium and low grades governor. Electric brushless Motor: Type : Brushless DC Motor Output Power: 1800W Voltage : 48V Speed: 4500rpm Motor Sproket : T8F 9T. Rated voltage: dc 48 v. Matching motor: dc brushless motorUnder Voltage Protection: 20V. 1 X controller box 1x Foot Pedal.1x T8F 29mm Sprocket 54T. For instruction video, please refer to the below youtube video.