The OSI-RE-SS can be a reflector- variety linear optical beam smoke detector intended to run being a element of fire alarm methods. The beam operates primarily on the basic principle of sunshine obscuration utilising an Infra-Purple beam. OSI-R-SS can be a 4-wire conventional reflector-variety linear optical beam smoke detector to https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/