Features: Analog-VU meter, with wired-stereo RCA-input and wireless microphone input, can match most common audional devices. Four channels can be input to different audional sources of the mixer simultaneously, and can also be output simultaneously to meet the requires of monitoring or recording. 4-Way audio-splitter box and VU2 can work in the 4-IN1-OUT mode to compare the sound quality of different audional sources, and can also compare preamplifier, headphone, amplifier, and active speaker in the 1-IN4-OUT mode. USB port of VU2 only used to supply power to driver board of VU instrument, without any interference to audional input and output circuits; VU meter and switcher box are independently controlled. VU meter only reads audional signals from I/O-port, without affecting sound quality. Quality input and output terminals, large contact area, perfect performances, low signal loss, and equipped with remote control, which is very convenient to use. Specifications: Material: Metal ColorL Black, Yellow(optional) Model: VU2 Audio-input: Stereo-RCA/Microphone Audio-output: 4 Groups of Stereo-RCA Working Mode of Switcher: 1-IN-4-OUT/4-IN-1-OUT Sensitivity Adjustment: support Gain-adjustment: support (DB-mode & ACG-mode) Working-voltage: USB DC5V Working Current: 0.5A (black) /1.5A (yellow) Voltages of Backlight-filament: DC-AC6 to 12V Current of Backlight-filament: 10mA (black) /100mA (yellow) Support: Dynamic Acceleration/deceleration Damping Modes, Power-on/off, Settings Saved After Shutdown, Mute-function & Remote Control Package Includes: 1 Piece VU Meter note: 4-channel can work (input or output) simultaneously, but only can be set by pressing the 4ch button on the front panel, cannot be controlled by remote control. When in 4-IN-1-OUT mode, channel of VU2 are not suggest parallel-work, there will be some distortion if the output level of 4 players are different. Not recommend to power VU2 from USB port of audional source devices, noise will be generated in this conditions.