This motor speed controller is suitable for AC 220/240V 50/60HZ motor. Speed regulation range is 90-1400r/min 50Hz, 90-1700r/min 60Hz. Suitable for packaging, printing, food, electronics, instrumentation, clothing industry production line for speed control drive device. The controller uses high quality electronic circuit and integrated components for durability. It has small size, high precision, wide speed controlling range, and long service life. Method of use: 1. Turn off the power, connect it according to the wiring diagram and make sure the connection is correct. 2. Fix the controller well and set the speed to the lowest "0", so as to avoid sudden large current and permanent damage when starting the power supply. 3. Then turn on the power and adjust the speed knob to the desired position. Please turn off the power when not needed. 4. The governor is connected to the motor. If the torque or speed is found to be inconsistent with the requirements, please adjust the fine-tuning potentiometer on the side of the product. 5. To change the running direction of the motor, simply replace the jumper lines of "CCW" and "CW" on the back of the controller. 6. Select COM and CW short connection, then the motor will rotate clockwise. 7. Select COM and CCW short connection, then the motor do counterclockwise rotation. Colour: black Material: ABS Package Contents: 3 x Motor Speed Controller Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.