The Kidde Silhouette low profile KN-COPF-i carbon monoxide alarm features a low profile design that fits discreetly into any modern decor. This AC/DC powered unit operates on a 120V power source fitting standard 2-gang, metal, or plastic electrical boxes, and includes a sealed Lithium-Ion rechargeable battery that lasts the 7-year life of the alarm. It features electrochemical CO sensing technology, a 9V battery backup, and an 85-decibel alarm. This unit will interconnect with up to 24 other Kidde carbon monoxide, smoke, or heat alarms and functions in temperatures from 40 to 100 degrees Fahrenheit and up to 85% humidity. The Silhouette alarm guarantees the smart homeowner the earliest warning of carbon monoxide danger or fire hazard.