This DC12V governor can be controlled according to the ambient temperature of the fan speed, no manual control, automatic stepless speed, the higher the ambient temperature, the faster the fan speed control, saving energy and reducing noise. Whether it is a 2-wire, 3-wire or 4-wire fan (only connect power cable), whether PWM or brushless fans, as long as the fan voltage is within 12V, current less than 1A, the governor apply! Also can drive a of fans (total current must