Features: The supply ranges is 4~12V, rateds is 5W (Do not overloads). Insert governor into phone charging treasure, insert the fan USB plug into the USB port of governor, and then turn the adjustment knob to adjust. Stepless speed regulation output voltages ranges 2.5V-8V stable change, so speed of the fan can be adjusted, greatly the comfort. Crafted from ABS, features USB input and a simple twist operation—clockwise to increase and counterclockwise to decrease fan speed for comfort. Suitable for hot days at your desk, in your dorm room, or while traveling, this USB fan controller transforms any ordinary fan into a customizable cooling experience. Specifications: Component:ABS Power:5W Power Supply Ranges:4-12V Output Ranges:2.5-8V Size:Approx.35mm/1.38inch Package Includes: 1Pc USB Fan Speed Controller note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.