Emergency Power Dimmer Control with automatic diagnostic and manual test features for 4 wire dimmable loads (0-10V and Low Voltage Digital Dimming). Allows switching and dimming of designated emergency luminaires during normal operation and automatically brings emergency luminaires to full brightness during a utility power interruption. 120-277V 50-60Hz, 20A magnetic ballast, 16A electronic ballast. Can be mounted flush or above a suspended ceiling. UL924