?This speed controller adopts high quality materials, with low loss and low heat ?The precision adjustable resistance has high accuracy and excellent performance, and the speed can be adjusted at will ?The cooling fan hub is equipped with an independent speed controller for you to adjust ?8-fan stepless variable speed upgrade, 4 knobs control speed regulation, one knob controls two fans ?Professional high-speed regulating circuit, high performance ?Support 3pin/4pin dual-type standard fan port Specification: ?Power Supply: 4-pin IDE ?Material: Plastic + Metal ?Power Supply Voltage: 0-12V ?Connectable Fans: 8 ?Adjustment Method: 4 Manual Adjustment Knobs ?Installation Position: PCI Position of PC Chassis ?Fan Interface: 4PIN (3PIN Can be connected) ?Size: 120 x 65 x 18mm/4.72 x 2.56 x 0.71" Notes: ?It is normal for the built-in resistor of the controller to heat up during use. In addition, there is a power limit and a single fan with a power exceeding 10W cannot be connected, otherwise the product may be easily damaged. The product is equipped with speed regulation chip and it is normal to heat up during use. As long as it is not overloaded, daily heat up will not affect the use. ?Due to the different monitor and light effects, the actual color of the item might be slightly different from the color showed in the pictures. Thank you for your understanding. ?Due to manual measurement, please allow a difference of 1-3mm.