The Fire-Lite-D355PL is a non-relay, Duct Smoke Detector with a photoelectric sensor. The sensor includes a SD355R remote test capable addressable low-profile photoelectric smoke detector. Able to operate in a broad temperature range, the D355PL is a versatile solution for a multitude of environments. Additional wiring space is providing by a 3/4" knockout. The detector mounts easily to a round or rectangular duct.The Fire-Lite-D355PL is a non-relay, Duct Smoke Detector with a photoelectric sensor. The sensor includes a SD355R remote test capable addressable low-profile photoelectric smoke detector. Able to operate in a broad temperature range, the D355PL is a versatile solution for a multitude of environments. Additional wiring space is providing by a 3/4" knockout. The detector mounts easily to a round or rectangular duct.