Fan Cooled 30 AMP PWM (Pulse Width Modulator) TECHNICAL SPECIFICATIONS: Power supply 12/24 VDC via. jumper Load voltage 12/24 VDC 30A max Output: PWM (Pulse-Width Modulation) for controlling DC loads. Output frequency : 100Hz. Adjust DC output range from 0% to 100% Instructions included Board size is 3.9"L x 1.7" W x 1.6"H TThe fan is for 12V systems only You will receive *30A PWM with cooling fan mounted* *Complete instructions with graphics*