xocome USB Fan Speed Controller, 5W Regulator, Stepless Adjustment, 3PCS, for 5V USB Fans, Model Name: USB Fan Speed Controller, Color: Green|White|Black|Grey

• Material: USB Fan Governor is made of electronic accessories element, inner conductor is pure copper. it is long lasting and durable for you to use.
• Rated Power: 5W (please DO NOT overload use), Suitable for common 5.0V USB fans
• USB Fan Speed Controller: The wind speed of the fan can be adjusted between 2.5V to 8V according to your comfort
• Instructions for Use: Plug the speed controller into your mobile phone charger or charging treasure, plug the fan USB plug into the speed controller USB port, then turn the adjustment knob to adjust the small and large airflow. Turning the knob clockwise will increase the airflow. Turning counter-clockwise will make the air volume softer. The knob has an on/off function.
• Package Includes: 3 pieces * USB fan speed controller

Fan speed principle: The non-adjustable USB fan is a 5 volt electric fan motor directly, while the two-speed fan has a boost circuit board inside. When placed in the second gear, the booster board raises the USB 5 volts. When the motor is connected, the air volume will be big. The stepless speed controller output voltage range varies from 2.5 volts to 8.0 volts, and the air volume is arbitrarily set! And the range is even wider! Turn the knob clockwise to increase airflow, counterclockwise to decrease airflow, knob with on/off function Range: -Power supply range: 4V to 12V -Output range: 3V-8V -Power rating: 5W（Do not overload） -Package Included: USB Fan Speed Controller x 3 NOTE: when using the two-speed adjustment fan, please put the fan in the first gear, otherwise it may not be able to adjust the speed.