The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning. First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency. Through early warning interconnect, when one alarm sounds, all compatible alarms will sound Battery backup provides continuous protection during power outages Alarm indicator visually identifies the unit that initiated the alarm Quick Connect Plug included allows for easy installation with no need to rewire