brk co400b first alert carbon monoxide detector 2aa battery powered

Basic 9V battery operated carbon monoxide alarm meets most codes, both state and local, for carbon monoxide alarms. Features: » Electrochemical Carbon Monoxide Sensor - the most accurate sensor available as compared to other sensing technologies» End of Life Signal provides audible notification alarms needs to be replaced» Single Button Test/Silence» Two silence features - can silence the low-battery chirp for up to eight hours or temporarily silence an unwanted nuisance alarm» 7-Year Limited Warranty Specs: » Sensor: Electrochemical» Warranty Claim: 7-Year» Package Type: Box» Color: White» Battery backup: N/A