The SL-2000 series duct smoke detectors will provide early detection of smoke and products of combustion present in the air moving through HVAC ducts in any commercial, industrial, or residential application. These devices are designed for the prevention of smoke re-circulation by the air handling systems, fans, and blowers. The SL-2000 is designed and built to meet all local requirements, as well as the NFPA regulations regarding duct smoke dectors. Output terminals are provided for remote accessories such as horns, strobes, remote status indicators, and test/reset key switches or pushbuttons. The Ionization and Photoelectric detector heads are interchangeable. Air sampling is accomplished via two tubes that protrude into the duct. An exhaust tube with a standard length of 7" is supplied in the installation kit with the unit. Once the duct size is determined, a sampling tube must be ordered. Four standard sizes including a 1', 2.5', 5', and 10' lengths can be ordered and cut to the correct size of the duct. The SL-2000 provides two sets of 10A form "C" and one set of a 2A form "A" alarm contacts, along with one set of 10A form "C" trouble contacts for monitoring head removal and supply voltage failure. The SL-2000 is covered by ACI's Two (2) Year Limited Warranty. "No-Tools Required" front or rear loading and removing sampling/exhaust tubes Interconnect up to 30 units for common functions Magnet test capability (magnet included) Unit includes green pilot and red alarm visual indicators