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, notebooks, and desktop computers. Supports Windows and Android systems. Features a Type-C interface for plug-and-play connectivity. Equipped with RGB lighting effect that can be turned off. Button functions can be customized using key mapping software. Instructions: Connect the USB cable to power on the device—the 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: Other items not included. Due to lighting and display differences, the actual product color may vary slightly from the image. Measurement may vary by ±1-3 cm.