ITEM NAME:9V 12V 24V 48V 60V 20A PWM DC Motor Stepless Variable Speed Controller VFF.Suitable for the DC motor (or DC load) within 20A. Current: 20A. PWM Frequency: 25kHz; Duty Cycle Adjustable: 5%-100%. TO CHANGE MOTOR DIRECTION, INTERCHANGE THE POSITIVE AND NEGATIVE WIRES OF MOTOR.