KIDDE analogue linear smoke detector, aritech ir transmitter/receiver barrier, ir radiation reflected by prism/mirror that analyses for smoke, suitable for high-level or inaccessible installations (maximum height 25 m), powered from the same loop. no external power supply required, ir 100m 2e/1s relay 2a 24v.coverage 100x15m, easy alignment and adjustment and testing. reduction of false alarms