Kidde FIREX Hardwire Smoke Detector with 9-Volt Battery Backup and Front Load Battery Door (4-Pack) 21027521

These alarms are equipped with two pre-stripped wires for easy installation and have a 9-Volt battery backup to ensure continued use during a power failure. The alarms feature a dust cover that protects the internal sensor from airborne contaminates that may take flight during a fire or a construction job.