Name:Electric Wrench Controller Board Voltage:18-21V Maximum output power:600W Size:6x5x0.6cm(2.36x1.97x0.24in) Before testing the machine, you must first connect the wire - fix the motor - install the case - tighten the screw - make sure that the square shaft of the head can be easily rotated without jamming - connect the power supply - down the speed control switch so that there is no in the shell! Otherwise, there may be a buzzing alarm! To prevent damage to the motherboard, please follow the requirement. Color:As Shown Material:Metal+Plastic Package Contents: 1 * Electric wrench control panel 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.