... size 3.High efficiency 4.Large torque brushless DC Motor for electric bicycle system functions:1. linear speed control,2 ... 8. sensorless,9. sleepRated Voltage:24V---48VPower:150W--240w Motor system functions: linear speed control, brake power-off, ... under-voltage protection, overload protection, motor block protction, speed limit, lose control protection, phase lost protection, hall lost protection, ...