USB Fan Speed Controller DC 4-12V Reducing Noise Multi-stall Adjustment GovernorModule 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! 1. Function Description: Suitable for the very common 5.0V USB fan on the market2. 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 4~12V4. Output Range:DC 2.5~ 8.0V5. 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! Package Content: 1 x Fan speed controller