This wheel hub motor is suitable for the rear wheels of bicycles with dropouts of 5.31 inches. Baking Process: The baking paint process makes it a strong waterproof ( IP65) and anti-rust ability. Low Noise: Due to a brushless gearless motor, it produces low noise when riding. Durable Material: This product is made of high-quality aluminum alloy and iron material, which is strong, durable, and not easy to deform. Long Power Cord: The long power cord (3.28ft) allows for added convenience and extraordinary mobility. Protection Sleeves: Two central shaft protection sleeves extend the service life of the wheel hub motor. Specification Color: Black Material: Aluminium Alloy, Iron Surface Treatment: Baking Process Suspension Type: Rear Motor Type: Brushless Gearless Motor Specific Uses For Product: Road Special Feature: Electric Brake Type: Disc Brake Power: 1000W Voltage: 48V Waterproof Rating: IP65 Rotational Speed: 460rmp Cable Size: 1.0m/ 3.28ft Dropouts: 135mm/ 5.31in Max. Torque: 50N.m Max. Efficiency: 89% Reduction Ratio: 1:1 Travelling Speed: 38-55km/h Suitable Bike: Dropouts of 135mm/ 5.31in Product Size(D*T): 20.5*20.7cm/ 8.07*8.15in Package Size: 30*30*30cm/ 11.81*11.81*11.81in Net Weight: 5.5kg/ 12.13lbs Gross Weight: 6kg/ 13.23lbs Package Included 1* Wheel Hub Motor All Needed Accessories