12V-40V 10A Modulation PWM DC Motor Speed Control Switch Governor  Features:  Control the speed of a DC motor with this controller. High efficiency， high torque， low heat generating. With reverse polarity protection， high current protection. Working Voltage: DC 12V - DC 40V. Control Power:0.01 - 400W. Static Current:0.02 A ( Standby ). PWM Duty Cycle:10% -100%. PWM Frequency:13 KHz. Material: Plastic， metal. Size:6cm x 7.5cm x 2.8cm Weight: 70g  Package included:  1 x PWM DC Motor Speed Control Switch<br> <br> With reverse polarity protection， high current protection.<br> <br> Control the speed of a DC motor with this controller.<br> <br> High efficiency， high torque， low heat generating.