Default volume control function: turn clockwise to decrease volume, counterclockwise to increase volume, and press the knob to mute. Compatible with various system devices including mobile phones, tablets, and desktop computers. Supports Windows and Android systems. Features a Type-C interface for plug-and-play connectivity. RGB lighting effect can be turned on or off. Button functions can be customized using the included key mapping software. Instructions: Connect the USB cable to power on the device; RGB light will illuminate. Press and hold the knob for 2 seconds to turn off the light; press and hold again for 2 seconds to turn it back on. Color: Black Material: Acrylic + Aluminum Alloy Package Contents: 1 x USB Volume Controller 1 x Type-C Cable Note: The package includes only the items listed above. Other products are not included. Due to lighting reflections and differences in display screens, the color of the item in the image may vary slightly from the actual product. Measurement error allowance is +/- 1-3 cm.