Adjustable USB Fan Speed Controller with Stepless Regulation for 4 to 12V USB Fan Compatible with Home and Office Use.

1. You can adjust the fan speed as desired. 2. Turn the knob clockwise to increase airflow, counterclockwise to decrease airflow. The knob also functions as a switch. 3. The continuously variable regulator's output voltage range is 2.5 to 8.0V, allowing for arbitrary adjustment of airflow. The range is even wider! 4. Suitable for common 5V USB fans on the market. 5. Suitable for various power sources such as computers, power banks, etc. Specifications: Item Type: Fan Speed Controller Material: Aluminum Input Voltage: DC4~12V Output Voltage: DC2.5~8.0V Rated Power: 5W Package List: 2 x Speed Controllers Note: Instructions for Use: Insert the controller into a mobile phone charger, power bank, computer USB port, etc., plug in the fan, and then plug it into the controller! Or use a 5.0V Micro USB port for power. For two-speed fans, please set the fan to one speed only; otherwise, you may not be able to adjust the speed!