The ControlKeeper 4A network lighting control panel is a cost effective specification grade lighting control system packed with plenty of standard features. Control up to 4 relays per panel with optional support for up to 4 0-10V dimming ballast control outputs. Network up to 254 ControlKeeper panels for a state-of-the-art lighting control system. Electrically held normally open, mechanically latched and two pole relays available. RS-232 port and RS-485 network standard.