Features 1、Reverse voltage protection 2、Over-current protection 3、Phase reversal control 4、The driver board can drive hard disk brushless motors, CD-ROM brushless motor and so on，the micro 3-wire or 4-wire without hall brushless motor. 5、Easily wiring Specification 100% brand new and high quality. Small size, light weight, large output. High reliability, good stability, strong adaptability, simple maintenance. So you can use it safely. Features: 2. Over-current protection 3. Phase reversal control 4. The driver board can drive hard disk brushless motors, CD-ROM brushless motor and so on, the micro 3-wire or 4-wire without hall brushless motor. 5. Easily wiring Specification: Condition: 100% Brand New Material: PCB Color: Green Speed Adjustment: 0%-100% How to identify the four-wire motor common port: Test these four terminals with the multimeter's resistance* gear, one of them the resistance of the terminal and the other three terminals is the smallest and equal. So this is a COM terminal. Size: Approx. 6 * 4.5 cm / 2.3 * 1.7 inch Weight: Approx. 22 g Package List: 1pc * 5V-12V DC Brushless Motor Driver Board Controller Note: 1.Please allow 1-3 cm error due to manual measurement. Thanks for your understanding. 2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. 3.Brushless motor line of receiving terminal drive plate must be pressed sturdiness, poor contact will lack of phase operation and burn out the chip.Board terminals fixed screw clearance, please use coarser line connected to the board.