In addition, this model was part of a large recall by Kidde in March 2018 over a manufacturing error that rendered one of the dual sensors inoperable. Free replacement alarms are available for defective units; you can find more information at the Kidde web site. If your home lacks a hardwired network of interconnected smoke detectors, and tackling the job of wiring a whole house smoke alarm system is too much for your DIY skills or contractor budget to allow, stand alone battery operated smoke detectors remain a reasonable second choice. Tops among these is the First Alert SA320CN Est. $20, a dual sensor, battery powered smoke detector that earns positive feedback overall. It's been tested by Consumer Reports, and earns the top rating for detecting both smoldering fires and flaming ones, though not a recommendation presumably because it cannot be interconnected with other alarms.