🔒 Safety You Can Trust! Advanced electrochemical sensor for accurate readings. Never worry about power failures. Continuous monitoring even during power outages. Your loved ones deserve the best safety. Easily fits any standard outlet. Plug-in with Backup Battery Operated Advanced Sensor The FIRST ALERT Carbon Monoxide Detector is a reliable, battery-operated alarm that ensures your family's safety by continuously monitoring CO levels, even during power outages. With an advanced electrochemical sensor, it provides accurate detection and peace of mind.