Module Highlights: USB Fan Air Conditioner Strong winds and weak wind adjust freely. Stepless Speed Regulation Fan Speed Regulation principle: The non-adjustable fan is a 5 v direct fan motor, while the two-stall fan is the interior has a step-up circuit board, when placed in the second gear, the boost plate will be USB 5 v up after the motor, the air volume is big. The stepless speed governor output voltage range of 2.5 v to 8.0 v between the smooth change, the amount of free air flow set and a wider range. Clockwise twist knob can increase the air volume, counterclockwise twist will reduce the air volume, and knob with switch function! Instructions: Plug the speed controller male connector into a mobile phone charger or computer USB charger, then plug the fan plug into the speed controller female connector. Alternatively, use a 5.0V Micro USB power adapter. 1. Function Description: Suitable for the very common 5.0V USB fan on the market 2. How to use: Governor male Insert mobile phone charger, charge treasure, computer USB, fan Plug and then insert the Governor head can! Or use the Micro USB 5.0V power supply. 3. Power supply Range:DC 4~12V 4. Output Range:DC 2.5~ 8.0V 5. Rated Power:5W (Please do not overload use) 6. Attention matters: For two-shift fan, please place the fan in one gear, or you may not be able to adjust speed! Color: Blue Material: PCB+Plastic+Metal Package Contents: 1* USB Fan Governor (Knob color is random)