Specification: Item Type: 20 inch Electric Bicycle Motor Wheel Kit Color: As Pictures Shown Weight: Approx.9400g/331.6oz Material: Stainless Steel + Aluminum Alloy + ABS Plastic Size: Controller Box: Approx. 148x83x42mm/5.8x3.3x1.7in, Meter: Approx. 80x48mm/3.2x1.9in Motor Type: Rear Drive Motor Wheel Motor Rated Voltage: 48V Motor Rated Power: 1000W Motor Speed: About 35-45km/h Motor Speed: 325-331 RPM Motor Torque (n.m): 57.5-59 N.M Motor Opening Size (mm): 135-142mm/5.3-5.6in Motor Matching Controller Current: 30A Motor RIM: P25D Motor Torque Arm: M14 Brake Disc for Motor: Approx. 160mm/6.3in Motor Brake Type: V Brake, Disc Brake Universal Motor Position: Rear Wheel Motor Structure: DC motor Motor Magnet Height: 30H Motor Magnet Pole Number: 46 Motor Operating Temperature: -20℃-45℃ Controller Rated Voltage: DC 36V/48V Controller Maximum Current: 30A Controller Speed Setting: 1-4.2V Controller Brake Input: Low Level Controller Booster: 1:5 Connector: Ordinary SM Connector LCD S866 Meter Working Voltage: DC 24V, 36V, 48V, 60V Compatible (meter Selection Setting). Package List: 1 x Motor Wheel 1 x Controller 1 x Meter 1 x Instrument Manual 2 x Power off Brake Lever 1 x Throttle Dial 1 x D12 Power Assist Sensor Wiring 1 x D12 Booster Sensor Booster Sheet 1 x D12 Booster Sensor Ring 2 x Cable Ties 1 x Controller Bag 1 x Manual Note: Use the product that complies with the communication protocol.