The OSI-RE-SS can be a reflector- sort linear optical beam smoke detector made to operate for a part of fire alarm units. The beam operates totally on the principle of sunshine obscuration utilising an Infra-Crimson beam. OSI-R-SS can be a 4-wire conventional reflector-form linear optical beam smoke detector for use https://socialwebnotes.com/story4049819/conventional-beam-detectors-options