Features: Inputs are powered by standard USB-A plugs (5V voltage) Output voltage adjustable from 2.5V to 8V (±0.5V) according to the knob Suitable for all kinds of USB-powered small devices for voltage regulation, such as USB fans, USB LED lights and so on. Turn the knob clockwise to increase the speed Turn the knob counterclockwise to reduce the speed Turn counterclockwise to close the output To avoid serious heat, it is recommended that the output power is controlled within 7W Material: PLA colour: Black Package Contents: 1 x USB Speed Controller 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.