Default volume control function, clockwise to reduce the volume, counterclockwise to increase the volume, press the knob to mute.Compatible with a variety of system devices, suitable for mobile phones, tablets, notebooks, desktop computers, compatible with Windoens and Andriod systems.Type-C interface, plug and play.RGB lighting effect, can be turned off.The software can customize the button function: with the key value editing software, different button functions can be customized. Instructions for use: Insert the USB cable, the RGB light turns on, press the knob for 2 seconds to turn off the light, and press the knob for 2 seconds to turn on the light. Default volume control function, clockwise to reduce the volume, counterclockwise to increase the volume, press to mute.Colour:BlackMaterial:Acrylic + Aluminum Alloy Package Contents:1 x USB Volume Controller1 x Type-C Cable 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.