This product is a stereo digital audio channel switcher with volume, treble, and adjustment functions, EQ, custom sound effects, noise isolation, and infrared remote control for one-touch switching. Control: 28 levels/2 dB, -14 to +14 Treble Control: 28 levels/2 dB, -14 to +14 Input Gain: 3.75 dB to 11.25 dB Maximum Input Signal: 1.2 Vrms Channel Separation, f=1 kHz Total Harmonic Distortion (): 0.01-0.1% Functional 1. Mute: the encoder twice in succession. In mute mode, rotate the encoder left or right to unmute, or the encoder twice in succession. 2. Volume: Rotate the encoder left or right to decrease the volume on the left and increase the volume on the right. 3. Treble: Short the encoder to illuminate the "H" LED, indicating the treble setting. Rotate the encoder left or right to change the parameter, also enabling custom sound effects. If the encoder is not pressed within 5 seconds, it automatically switches to volume up or down. 4. : Short the encoder to illuminate the "L" LED, indicating the setting. Rotate the encoder left or right to change the parameter, also enabling custom sound effects. If the encoder is not pressed within 5 seconds, it automatically switches to volume up or down. 5. Channel Switching: and hold the encoder for 2 seconds to switch between CH1 and CH4. 6. EQ Sound Effect: the EQ button on the remote control. 7. Power Supply: DC 5V, stable operation with less than 100 mA. Power sources include USB ports on devices, computers, mobile phone chargers, and other devices with USB ports. Operating Voltage: DC 5V, 100 mA Volume Control: 63 levels/1.25 dB Color:Black Material:Aluminum Alloy Package Contents: 1 * Audio Switcher 1 * Remote Control 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.