The OSI-RE-SS is often a reflector- kind linear optical beam smoke detector intended to work as being a part of fireplace alarm devices. The beam operates primarily on the principle of sunshine obscuration utilising an Infra-Pink beam. OSI-R-SS is actually a 4-wire conventional reflector-form linear optical beam smoke detector for https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/