The Kidde KN-COPF-i Carbon Monoxide Alarm is a low profile AC/DC powered unit that operates on a 120V power source. The sealed in rechargeable battery backup lasts the 7-year life of the alarm to provide a maintenance free design. This alarm uses advanced electrochemical CO sensing technology, providing reliable protection against the dangers of carbon monoxide. The battery backup feature provides continuous monitoring of CO levels, even during power outages when AC-only units do not provide protection. This unit will interconnect with other Kidde CO and smoke alarms to provide the earliest warning of a CO or fire hazard. The Digital Display feature allows for easy viewing of carbon monoxide levels from 30-999PPM (parts per million). This CO alarm is available in a 6-piece cut case with tray for easy display. The Silhouette CO is a UL Listed product with a 7-year limited warranty.