Fire-Lite D365PL Duct DetectorThe FireLite D365PL intelligent non relay photoelectric duct smoke detector and DNRW watertight non relay photoelectric duct smoke detector feature a pivoting housing that fits both square and rectangular footprints capable of mounting to a round or rectangular duct. The DNRW duct smoke detector, with its NEMA 4 rating, is listed as a watertight, UV resistant enclosure providing protection against falling dirt, rain, and windblown dust, splashing and