The First Alert PRC700 Combination Smoke and Carbon Monoxide Alarm is designed to provide the same trusted functionality with a new, slim profile that blends into your home décor. This smoke and carbon monoxide detector provides comprehensive detection by featuring a sensitive photoelectric smoke sensor and an advanced electrochemical carbon monoxide sensor. The battery-operated smoke and CO detector can be installed easily, with no wires or electrician required. It has one-touch alarm silencing and test feature, and will continue monitoring during power outages. The twist-lock mounting system on this detector makes replacing batteries easy.