The drive board can drive hard disk brushless motors, CD-ROM brushless motors, and so on. It supports 3-wire or 4-wire brushless motors without Hall effect. It features reverse voltage protection, overcurrent protection, and phase inversion control. Drive Voltage: DC7-12v Working Current: 1.2A Speed Adjustment: 0%-100% Note: The brushless motor wiring to the receiving terminal of the drive board must be pressed firmly. Poor contact will result in missing phase drive and burning out the chip. Short circuits are fixed by screw spacing; use a thicker wire connected to the board. How to identify the common port of a four-wire motor: Use the resistance gear of a multimeter to test these four terminals. One of the terminals will have the minimum resistance value to the other three terminals. That is the COM terminal. Size: 6 x 4.5 cm / 2.36 inches x 1.77 inches Quantity: 1 Pc Color: Green Material: Plastic Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you. Package Contents: 1 Pc x DC Brushless Motor Drive Board Controller Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3 cm.