D2-AUS
Conventional duct housing with 2151 detector, no relay, no tube
D4120
4-Wire Photoelectric + Relay Duct Smoke Detector (stand-alone only)
D4120W
Watertight 4-Wire Photoelectric + Relay Duct Smoke Detector
RTS151KIT
Remote indicator and test panel with key-switch enabled test mode for duct and beam detectors