Super material: It is made of PC+metal. it is long lasting and to use. Package including: 3 pack of fan DC governor module. Stepless speed regulation output voltage range in 2.5V-8V stable change, so that the wind speed of the fan can be adjusted, greatly improve the comfort. PWM DC Motor Governor specification: The Power supply range is DC 4~12V, rated power is 5W (Do not overload). The current in the same product is up to 5A. Potentiometer with switch function. Directions for use: Insert the governor into the phone charger or charging treasure, insert the fan USB plug into the USB port of the governor, and then turn the adjustment knob to adjust the small air volume and large air volume. Turn the knob clockwise to increase the air volume. Turning it counterclockwise make the air volume gentler and the knob has a switch function. A wide range of applications: It is suitable for the speed regulation of DC motor, fan, fish tank oxygen pump and other products. Colour: as shown Package Contents: 3 * Fan Air Volume Speed Regulation Module Only the above package content, other products are not included. Note: Light 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.