With forward and reverse switch, potentiometer knob with switch, forward and reverse can be controlled by PLC. The forward and reverse switch can be replaced with a jog switch. The display tube and the module are connected by a cable. The cable may loosen and fall off during delivery. need to insert it tightly by themselves. If you mind, 't take pictures. With 0- digital scale positioning. Make that the positive and negative connections are powering on, and the wiring should not touch the heat sink, which may burn the circuit board. Note that this is not a power module, and the motor must be connected to adjust the speed. If the motor is not connected, the output of the multimeter will not change, and it cannot be connected to AC. For brushed motors. Input : DC 10-55V ( to the rated of the motor) Output : linear under load Maximum current: 60A Continuous current: 40A Speed regulation type: current regulation Speed regulation mode: potentiometer (linear) Support motor: DC brush motor Forward rotation reverse: Support Speed range: 0 -100% Control frequency: 15KHz Wiring type: terminal Knob Specification: 100K (with switch) Wiring type: fence terminal block Product weight: 170g Note: Electric bicycles cannot be used, including electric bicycle motors. The input must be divided into positive and negative can not input 220V household electricity. The input should be to the rated of the motor (within 10-55V). The digital display is the motor full speed percentage 0-100, not the actual speed of the motor. The input must be divided into positive and negative. The input should be to the rated of the motor within 10-55VDC. Colour:Green + Silver + Black Material:PCB + plastic + metal Size:100MM x 76MM x 28MM Package Contents: 1 x Speed Controller Module 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.