Wheel Diameter (inches): 20/26/27.5/28 And 26*4 Inches(Fat tyre Bicycle) , Construction Gear drive : BLDC hub motor with inbuilt planetary box , Rated Voltage (DCV) : 36, n0 (rpm): 290;250 , Rated Power (W) : 250 , nT (rpm): 255;220, Max Torque 32 N.m, Efficiency : 83.5%, Motor Weight (kg): 3 , Noise Grade (dB): <55 Operating Temperature : -20 to 45? , Reduction Ratio: 1:4.42, Color : Chrome, Application: Electric bicycle,