SD505-DUCTR Addressable Duct Smoke Detector and Housing with Relay .

The SD505-DUCTR addressable duct smoke detector with relay is a heavy duty detector housing with the SD505-APS addressable photoelectric smoke detector pre-installed and is used for detecting smoke and products of combustion present in air moving through HVAC air handling systems. The built-in relay can turn off fans, blowers and other devices.