The OSI-RE-SS can be a reflector- variety linear optical beam smoke detector intended to function as being a component of fireplace alarm programs. The beam operates primarily on the principle of sunshine obscuration utilising an Infra-Crimson beam. Shut/span> You can not access this page as this item just isn't obtainable https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/