Black. Once this Infrared Exit Detector from Camden Door Controls detects movement it sends a signal allowing you to perform the next action in the system, be it opening the door, sounding a buzzer or turning a light on. It can be installed up to 3m high, has a 0.1 to 0.2 second response time and a relay hold time of 0.5 seconds.. Active infrared. IP45 weather resistant. Can be installed up to 3m high. 0.5 second relay hold time