The Industry's ONLY Weathertight Duct Smoke Detector to boast NEMA 4X rating is now available! Check the single-latch closure - no screws to slow you down. And a one-piece cover! Compatible with all legacy APC detectors, sample tubes and remote accessories. Our timed Maintenance Mode allows servicing with no extra trouble reports to the system. The next generation of trade-dedicated terminal blocks help HVAC, Fire and Electrical installers from pirating terminals...