The Edwards Signaling SD-T78 SuperDuct 70" Air Sample Tube ensures easy installation with a slim profile under 2" deep, ideal for tight spaces. It features a PCB-mounted photoelectric sensor equipped with onboard intelligence and patented differential sensing for environmental compensation, guaranteeing stable, reliable smoke detection. Designed for high air velocity ducts up to 4000 ft/min, it supports standard Kidde Intelligent smoke detectors and offers a wide sensitivity range from 0.79% to 2.46% per foot obscuration. Compatible with the four-wire Duct Smoke Detector SD-4WJ, it includes a detector base that is prewired and ready for simple plug-in installation. Upgrade your smoke detection system with this efficient and intelligent device today!