120V AC/DC Photoelectric Smoke Alarm, With Carbon Monoxide Alarm, Be alerted to the type of danger and its location in your home with the First Alert SMCO100V-AC Interconnect Hardwire Combination Smoke & Carbon Monoxide Alarm with Battery Backup and Voice & Location Alerts. Easily install using the quick connect plug. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning. Also the alarm is also equipped with First Alert's Precision Detection advanced sensing technology and meets new industry standards.