FAN SPEED CONTROLLER USB MODULE 5W DC 2.5-8.0V. FAN SPEED CONTROLLER USB MODULE 5W DC 2.5-8.0V Feature:1. With this USB fan speed control module, you can easily adjust the speed of the USB fan for more efficient heat dissipation. 2. The output voltage of the stepless speed controller changes smoothly between 2.5V-8V, making it easy to adjust. 3. You can turn the knob clockwise to increase the volume of air , you can also turn counterclockwise to make the air flow softer. 4. The knob has a switch function, making operation very easy , and simple installation can also be completed quickly. 5. Adopting high quality printed circuit board, USB fan speed control board is very durable for long - term use. . FAN SPEED CONTROLLER USB MODULE 5W DC 2.5-8.0V Specification: Item Type: USB Fan Speed Controller Product Material: Printed Circuit Board Power Range: DC 412V Output Range: DC 8.0V Rated Power : 5 W Function: Stepless speed control at fan speed . Package List: 1 x USB Fan Speed Controller 1 x Nut 1 x washer . FAN SPEED CONTROLLER USB MODULE 5W DC 2.5-8.0V