Kramer Electronics VP-23 VP-23 is a 4x1 composite video, a 4x1 s-Video (Y/C) and a 4x1 computer graphics switcher each with unbalanced stereo audio. It is designed for a wide variety of presentation and multimedia applications. High Bandwidth - 315MHz (-3dB) computer graphics video, s-Video (Y) 260MHz (-3dB), 470MHz (-3dB) composite video. HDTV Compatible. Audio and Computer Graphics Video Level (Gain). Controls. Microphone Input Level Control. Master Audio Output - Input selectable. Talk Over Button - Microphone input signal mutes the line Audio output when a microphone detects sound. Control - Front panel and RS-232 (K-Router Windows - based software is included). Standard 19inch Rack Mount Size - 2U.