The OSI-RE-SS is a reflector- kind linear optical beam smoke detector made to function as being a component of fireplace alarm devices. The beam operates primarily on the principle of sunshine obscuration utilising an Infra-Crimson beam. Close/span> You can't entry this page as this solution will not be out there https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/