First Alert Z-Wave Plus Battery-Powered Photoelectric Smoke and Carbon Monoxide Detector w/Wi-Fi 1 pProtect your family from harm with this First Alert battery powered smoke and carbon monoxide detector. Photoelectric smoke sensing technology detects slow, smoky and smoldering fires and reduces nuisance alarms caused by shower steam or cooking smoke. This detector also alerts you at the first sign of carbon monoxide, helping you avoid exposure to potentially fatal gas. The voice and location feature notifies you of dangers origin, so you can easily