1、Large input voltage range from 9~60VDC,suitable for different power source. 2、The knob switch can adjust the motor speed steplessly. 3、With the digital panel,it is easy to read the value. 4、The speed controller is made of premium material,durable and has long service life. 5、The motor controller is stable and has great performance while using. Features: Large input voltage range from 9~60VDC,suitable for different power source. The knob switch can adjust the motor speed steplessly. With the digital panel,it is easy to read the value. The speed controller  is made of premium material,durable and has long service life. The motor controller is stable and has great performance while using. Specification: Input Voltage:DC 9~60V Output Voltage:Linearity under load Output Current: 20A Speed Adjustment Range:0~100% Control Frequency: 21KHz Speed Adjustment Mode:Knob Digital Display Positioning:0~100% Connection Type:Electric Wire Suitable for:DC Brush Motor Size:52 * 90 * 36mm / 2.05 * 3.54 * 1.42in Connection Method: NO Color Signal 1 Red Power + 2 Black Power - 3 Blue Motor + 4 Green Motor - Package List: 1*Speed Controller