High quality rotary switch.Hot-swappable (no need to reboot computer). Super mini size:Easy to place and suitable for your desktop and office Plug and play:No power supply and other software required; 't affect sound quality. Analog signal maximum support 2V p-p input and output. Input and output frequency range: 20Hz - 20KHz.Use standard audio cable, input transmission distance up to 8 meters, output transmission distance up to 8 meters Channels:4 Model Number:Headphones Amplifier Type:Mini Amplifier Recommended Headphone Maximum Impedance:Less than 32 Ohm Output Type:LINE OUT (AUDIO OUT) Input Type:LINE IN (AUDIO IN) (The product appearance and printed words depending on the batch, but this does not affect use) Color: As Shown Material: ABS Package Contents: 2 x HIFI Stereo Audio Switcher 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.