Specifications:- Overall Dimension(Dia.xW) 16 9/16" x 8 7/16"- Compatible Tire Size 20" x 4"- Rim Diameter 16 9/16"- Hub Length 9 7/16"- Rear Dropout Spacing 6 11/16"- Motor Diameter 9 1/2"- Spokes Length 2 13/16"- Spoke Screw Type 12G- Controller Power 1000W- Controller Voltage 48V- Motor Speed 510 Rpm- Hub Torque 58.5 N.m- Compatible Battery 48V 20 Ah- Suitable Brake Type Disc / V-brake- Weight Capacity 330 Lbs- Climbing Angle 20 Degrees- Net Weight 23.6 Lbs. Package Contents:- 1x Motor Wheel- 1x Controller- 2x Brakes- 2x Throttle Sleeves- 2x Twist Throttles- 1x Lcd Display- 1x Pas Sensor- 1 Set of Flywheel- 1 Set of Torque Arm- 10x Wire Ties- 1x Spoke Adjuster- 2x Winding Pipes. Notice: - Battery, charger and tire are not included, please prepare them before using.- The electric wheel is only applicable to conventional bicycles, not for tricycles, tractors, etc.- Please go to automobile repair shops with standard business license for modification.