Features: Brand new and high quality Use high-quality materials, durable. The fan wind speed can be conveniently adjusted by rotating the potentiometer. Support simultaneous control of up to 9 fans. The duty cycle can be adjusted by 0% - 97%, and the speed range is wide. Wide range of use. Specifications: PWM frequency is 25KHZ, which can adapt to most 12V adjustable speed fans on the market Input voltage: 12V Can support current 2A max Duty cycle adjustable:0% - 97% 9 fans can be controlled at the same time Plate size: 50mm x 38mm Weight: 21g Note: Be careful not to block the fan blades, and the minimum wind speed is assumed when the power is turned on. Connect 12V voltage through 6pin or 4pin ATX interface or terminal block. Turn the potentiometer clockwise to increase the wind speed gradually. Package includes: 1 x Fan Speed Controller