Specifications: Overall Dimension(Dia.xW): 25 13/16" x 1 3/4" (65.5 x 4.5 cm) Compatible Tire Size: 26" Rim Diameter: 22 7/16" (57 cm) Axle Length: 8 1/4" (21 cm) Rear Dropout Spacing: 5 5/16" (13.5 cm) Motor Diameter: 9 1/2" (24.2 cm) The Number of Spokes: 36 Spokes Length: 6 5/16" (16 cm) Spoke Specification: 12G Controller Power: 1000W Motor Voltage: 48V Motor Rotating Speed: 440 RPM Motor Torque: 33.2 ft-lb (45 Nm) Recommended Battery Specification: 48V/30A Recommended Battery Capacity: 17 to 20Ah Suitable Brake Type: Disc Brake / V-Brake Suitable for Maximum Flywheel Speed: 6/7 Level Weight Capacity: 220 Lbs (100kg) Climbing Angle: 12 Degrees Net Weight: 24.7 Lbs (11.21 kg) Package Contents: 1*26" Rear Wheel with Brushless Hub Motor 1*Battery Connection Cable 1*Electric Controller 2*Hand Brakes 2*Handle Grips 1*Thumb Throttle 1*Controller Bag 1*Set of Winding Pipe and Cable Tie 2*Terminal Boxes 1*Manual 1*Spoke Key Notes: 1. This kit includes a 26in front wheel (battery and tire are excluded). Please measure the size of your existing tire before purchasing. 2. Please note that it is only suitable for front-wheel installation on two-wheeled bicycles. It cannot be used for three-wheeled or multi-wheeled vehicles. 3. When connecting the controller to the wires, please make sure to connect the correct color to it. Otherwise, the controller may be damaged.