The OSI-RE-SS is usually a reflector- variety linear optical beam smoke detector made to work like a ingredient of hearth alarm systems. The beam operates totally on the principle of light obscuration utilising an Infra-Pink beam. OSI-R-SS is usually a four-wire conventional reflector-variety linear optical beam smoke detector to be https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/