Module : USB Fan Strong winds and weak wind adjust freely. Stepless Speed Regulation Fan Speed Regulation principle: The non-adjustable fan is a 5 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 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 set and a range. Clockwise twist knob can increase the air volume, counterclockwise twist 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 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 to adjust speed! Color: Blue Material: PCB+Plastic+Metal Package Contents: 1* USB Fan Governor (Knob color is random) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Note: Please allow 1-3 mm error/1-3g weight error and actual product color may vary due to lighting conditions.