The SL-2000 Series Smoke Duct Detector is the latest innovation for early detection of smoke and products of combustion present in air moving through HVAC ducts in Commercial, Industrial and Residential applications. The SL-2000 is designed to prevent the re-circulation of smoke by the air handling systems, fans, and blowers. Complete systems may be shut down in the event of smoke detection. Output terminals are provided for remote accessories such as horns, strobes, remote status indicators and test/reset key switches or push buttons.