SC9120LBL 120V AC/DC Smoke and Co alarm - 10Yr Lithium battery - locked battery drawer 120V AC/DC ionization Smoke/Co alarm with a 10Yr Lithium battery back-up. The battery drawer is shipped pre-locked so battery will not be discarded prematurely. Under normal conditions you should not have to replace the battery for the life of the alarm. 10Yr battery backup saves time and money on annual maintenance costs. 10Yr Lithium battery backup; locked battery drawer; electrochemical carbon monoxide sensor - the most accurate sensor available as compared to other sensing technologies; latching alarm indicator - remembers which unit initiated an alarm; intelligent sensing technology helps reduce the number of nuisance alarms; perfect mount - allows for easy alignment of alarm; single button test/silence; easy installation/maintenance - preferred features include a large opening in the mounting bracket for easy access to wiring. Keyhole slots in the mounting bracket eliminate the need to remove the electrical box screws for installation. A battery pull tab keeps the battery fresh until the home is occupied. Battery installation and removal can occur while the unit is mounted to the ceiling or wall via the side load battery compartment. Two locking features are provided to prevent battery theft and/or theft of the unit. Connection to AC power is made with a ''quick-connect'' wiring harness. Installation is Quick, easy and cost effective; dust cover; 10-year limited warranty