First Alert SMCO210 10-Year Battery 2-In-1 Photoelectric Smoke & Carbon Monoxide Alarm with Slim Profile. Uses First Alert's Precision Detection advanced sensing technology and meets new industry standards. This 2-in-1 alarm provides convenient protection against both fire and carbon monoxide (CO). The alarm is also equipped with a 10-year sealed battery to eliminate the need for battery replacements and low battery chirps.
