Function- Solve the problem of 3Pin or 4Pin interface is not enough, change the different interface can adjust the fan speed. 12V Cable- Two 12V power, 12V fan that is normal full speed operation (12V for the yellow and black wire). 7V Cable- One 7V power supply, 12V fan using 7V can reduce the speed and wind noise! (5V is red and yellow wire). 5V Cable- One 5V take power, 12V fan using 5V can reduce the speed, reduce wind noise! (5V is red and black wire). Note- Individual power supplies do not support 7V, you need to unplug the 7V cable and restart the computer.