The VSA-31 Mini-Cat® is a 3 input A/V Switcher on a 4-gang wallplate transmitter and remote receiver. The VSA-31® provides individual buttons for turning the projector on/off and selecting the video source for display. It sends the selected AV to a remote receiver unit via 2 Cat5 Cables. No power supply is needed for the wallplate. The remote unit can be up to 750 ft away and has a built-in 12 Watt Stereo Amp which can drive a pair of 8 or 16 ohm speakers directly. A line output is provided for connection to an external amp if necessary. A Volume knob on the wallplate allows adjustment of the sound level. The VSA-31® automatically controls projector operation (on/off and source selection) via serial commands stored in the unit by just the touch of a button.