APOLLO Discovery Marine Optical Smoke Detector 58000-600 MAR The Discovery Marine Optical Smoke Detector works on the light scatter principle and is ideal for applications where slow burning or smouldering fires are likely. • Responds well to slow burning, smouldering fires • Well suited for accommodation decks, passages and escape routes • Unattected by wind or atmospheric pressure • Rejection of transient signals • Remote test feature • Five EN54 approved response modes