The OSI-RE-SS is actually a reflector- kind linear optical beam smoke detector meant to run like a component of fireplace alarm programs. The beam operates primarily on the basic principle of light obscuration utilising an Infra-Red beam. OSI-R-SS is usually a four-wire conventional reflector-kind linear optical beam smoke detector to https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/