Back-up source for Delay OFF in case of voltage failure (emergency lighting, emergency respirator, or protection of el. controlled doors – in case of fire).Function Features :Time range (adjustable by rotary switch and fine setting by potentiometer): 0.1 s - 10 min. Voltage range: AC/DC12-240V , clamp terminals.  status is indicated by LED.  1-MODULE, DIN rail mounting.