The OSI-RE-SS can be a reflector- style linear optical beam smoke detector made to function for a ingredient of fire alarm methods. The beam operates primarily on the theory of sunshine obscuration utilising an Infra-Purple beam. OSI-R-SS is a 4-wire conventional reflector-type linear optical beam smoke detector for use in https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/