Battery-operated carbon monoxide (CO) alarm provides continuous monitoring of CO levels and will sound a loud warning signal if elevated CO levels are detected, even during power outages. Battery lockout system deters covering battery compartment without installation of batteries. Slide-out battery door cover gives immediate access to batteries. Test/reset button tests unit for proper operation and resets carbon monoxide alarm. Red LED will pulse and a loud alarm pattern will sound when a dangerous level of carbon monoxide is detected. Green LED flashes every 30 seconds, indicating unit is operating properly. Power Source(s): 3 AA; Mounting: N/A; HUB Compliance: N/A; Compliance, Standards: N/A.