eatures:   1. Three-hole output: Three-hole output, with a two-in-one headset and a separate headphone jack, which can support two people at the same time.   2. Singing or voice: support microphone or audio connection, create a family KTV, voice connection video chat more fun.   3. Adjust the volume: The external volume adjustment knob can freely adjust the volume level. At the same time, the headset or microphone mute switch button is added, which is convenient to use.   4. Suitable for most earphones: compatible with mainstream equipment, support TRS and TRRS two modes, compatible with most earphones, can convert the analog signal output from the interface of tablet computer, notebook, desktop computer, audio, etc. into digital signal output.   5. Driver-free sound card: Plug and play, driver-free supports operating systems such as Windows/ Mac os/ Linux, no driver is required.   Description:   The USB multi-function external sound card can bring you shocking sound effects when playing games and watching TV series.   Specifications:   Input interface: USB 2.0   Output interface: microphone interface, headphone interface, 4PIN headset composite interface   Signal to noise ratio: ≥80dB   Frequency response range: 15HZ-25KHZ   Headphone indicator: blue   Microphone indicator: red, lights up when muted   Other functions: mute switch, volume adjustment   Support system: Windows / Mac OS / Linux   Cord length: 10cm   Package Included:   1 * USB External Sound Card (without battery)     Notes: 1. Please allow 0-1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from real object.