First Alert BRK 10-Year Battery AC Hardwired Combination Smoke and Carbon Monoxide Detector

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. 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.