The OSI-RE-SS is usually a reflector- kind linear optical beam smoke detector built to work as being a component of fire alarm techniques. The beam operates primarily on the principle of light obscuration utilising an Infra-Red beam. OSI-R-SS is usually a 4-wire conventional reflector-sort linear optical beam smoke detector for https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/