Three-hole output: The unit provides a three-hole output that supports a TRRS headset and a separate headphone jack, allowing two devices to be used at the same time. Singing or voice: Supports microphone input or audio connection, enabling family KTV and more enjoyable voice chats during video calls. Adjust the volume: An external volume knob lets you easily adjust the level. A headset or microphone mute switch is included for quick, convenient control. Suitable for most earphones: Compatible with mainstream devices and supports both TRS and TRRS modes. Works with most earphones and can convert the analog signal output from tablets, notebooks, desktops, and other audio devices into digital output. Driver-free sound card: Plug and play. Supports Windows, macOS, and Linux; no driver required. Use scenarios: - At home KTV with family: connect a microphone and headphones for shared singing and fun during video calls. - Online meetings and streaming: use as the mic/audio interface for clearer voice in Zoom, Teams, or live broadcasts. - Gaming and social chat: enable in-game voice chat and party chat on PC or tablet without setup hassle.