First Alert Hardwired 120V Electrochemical/Ionization Carbon Monoxide and Smoke Alarm Brand_Comfort Zone 1-piece solid core design is

1-piece solid core design is up to 5 times more durable than the current 2-piece conventional product

hand wheel installation

(1) 15/64"

Excellent Replacement For Qest & Flare It Type Fittings

First Alert Hardwired 120V Electrochemical/Ionization Carbon Monoxide and Smoke Alarm Brand_Comfort Zone 1-piece solid core design isElectrochemical & ionization sensor Designed for hardwired installation, but features a 10 year battery back up allowing the unit to function if the power goes out Hardwire adapter so there is no need to rewire Can be connected to other compatible BRK or First Alert CO smoke detectors within a single family residence Includes single button silence or test function 10 year limited warranty