First Alert is the category leader in fire safety and delivers reliable life safety products that help our consumers protect what matters most through innovation and performance. Carbon monoxide (CO) is the leading cause of accidental poisoning deaths in America, yet many people don't know they are suffering from CO poisoning until it???s too late. Symptoms of carbon monoxide poisoning are like the flu and you might not even know you're in danger. The CO910B 10-Year alarm detects the CO you can't see, smell or taste in the air. It features a slim, square design with versatile mounting placement. Plus, this alarm does not require battery replacements for the 10-year alarm life. This First Alert CO910B Carbon Monoxide Alarm is an essential product in protecting your home and family.