The First Alert SMCO500V Interconnect Battery-Operated Combination Smoke Carbon Monoxide with Voice Location Alerts helps provide an early warning and guide your escape to safety. Also equipped with First Alert's Precision Detection advanced sensing technology that meets new industry standards. 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 Voice location alerts tell you what the danger is and its location to help you escape safely Battery-operated alarm is easy to install and maintain Provides reliable 2-in-1 protection against both smoke and carbon monoxide