The OSI-RE-SS is usually a reflector- style linear optical beam smoke detector built to function to be a part of fireplace alarm methods. The beam operates primarily on the principle of sunshine obscuration utilising an Infra-Red beam. OSI-R-SS can be a 4-wire conventional reflector-style linear optical beam smoke detector to https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/