The First Alert SMCO500V Interconnect Battery-Operated Combination Smoke and Carbon Monoxide (CO) Alarm with Voice and Location Alerts helps provide an early warning and guide your escape to safety. This combo detector is also equipped with First Alert's Precision Detection advanced sensing technology that meets the latest industry standards. First Alert's Precision Detection advanced sensing technology complies with the latest industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.