Feature: High-quality materials housing, matte anti-fingerprint, one-button non-slip rotary button, more comfortable touch and scratch resistance than plastic cover. USB plug and play. 360-degree rotatable arc button, easy to use (volume adjustment, mute, up and down, pause), and avoid discomfort caused by sharp edges. Non-slip mat. There is a soft pad at the bottom, which is stable and non-slip during use. Lossless sound quality. Adjust the o source directly without affecting the o quality. Suitable for use with desktop or laptop. Broad compatibility. Support for WIN 7/8/10/XP, VISTA, Android, iOS (mobile phone requires a compatible USB adapter cable). Specification: Name: USB volume controller Installation: USB driver-free Mode: Button to switch dual mode Applicable to: Windows, OS Note: If your device can use a USB mouse and keyboard, you can also use our USB volume controls. Material: Plastic Color: Black Package Contents: 1 x PC Computer Speaker Volume Controller Knob 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 to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.