3Pin/4Pin Fan Hub:It can connect 8 fans at the same time. After connecting to SATA Interface for power supply, it can realize speed change by rotating the rotary knob. Widely used for PC computer water cooling system. (1 knob to control 2 fans), the wind speed can be adjusted as needed. Please note:The governor has a power limit, a single port can support a maximum current of 0.6A, it cannot be used beyond the standard, and a single fan with a power exceeding 10W cannot be connected, otherwise the product will be easily damaged Save space:8 Channels Fan Hub The governor is installed in the PCI position of the chassis, which is convenient for installation and does not take up space,External knob, speed regulation is more convenient Cooling Fan Speed Controller Material:4 Knob Cooling Fan Speed Controller adopts plastic and metal materials, durable, reliable, with low loss and low heat. 8-Port Cooling Fan Hub:The speed is infinitely variable from 0-12V in the full range. If the fan and the light are integrated, the brightness of the light will also change when the speed is adjusted.