Metal housing. Aluminum alloy anti-fingerprint, one-button non- 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.Computer sound desktop control. Quickly adjust the volume, say goodbye to the mouse and keyboard, rotate the button to quickly adjust the computer volume.Bluetooth-compatible mode. Install a wireless Bluetooth-compatible computer to the shackles of wired. Built-in Bluetooth-compatible 5.1 chip, stable and fast transmission, and the barrier-free distance can reach 15 meters; connect to a Bluetooth-compatible speaker, the computer sound is transmitted to the Bluetooth-compatible speaker/amplifier, and the endless and music in the Internet world can be transmitted to the speaker and power amplifier. enjoy the charm of music.External sound card mode. The computer is equipped with an external sound card, without loss of sound quality. In the computer external sound card mode, you can monitor the computer sound by simply inserting the headphones into the 3.5mm headphone .Small and easy to go. Less than the size of a mobile phone, suitable for office work, easy to carry.Name: PC volume controllerBluetooth-compatible version: Bluetooth-compatible 5.1Bluetooth-compatible protocol: A2dp/avctp/avdtp/avrcp/hfp/spp//att gap/gatt/rfcomm//l2capMusic formats: MP3, WMA, APE, FLAC, AAC, MP4 , M4A, WAV, AIF, AIFCSignal-to-noise ratio: equal 90dBMode: Bluetooth-compatible mode, external sound card mode, volume control modeInstallation : USB driver-freeCompatible system: for WinXP 7 8 10, for Macos, plug and play, no driver requiredColour:blackMaterial:MetalPackage Contents:1 x USB volume controller1 x USB data cableOnly 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.