Panasonic WJ-MP204C Data Multiplex Unit, Four camera inputs and selection, Alarm resetting and suspension, Camera communication data mode or with Martix Switcher WJ-SX350, or Matrix System 500, Built-in two way data communications modes for suite system application. Panasonic Security Data link mode for Optional System Controller WV-CU360C with Video Multiplexer WJ-FS309 and WJ-FS316.