Be sure to keep your home protected in case of smoke or carbon monoxide in your home with this First Alert Alarm. This has been proven to last for 10 years without an additional power source and is built with an array of convenient features. Use the First Alert Smoke and Carbon Monoxide Alarm to make sure your house is ready to detect a emergency Photoelectric smoke sensing technology detects commonly produced smoke particles in the event of a smoldering fire Electrochemical carbon monoxide sensing technology Perfect for apartment, dormitory, or hotel applications Voice warning functionality produces 85 dB alarm sounds to provide the programmed location of the unit when danger is detected Test/silence button mutes unnecessary alarms Sealed, tamperproof alarm locked to mounting bracket to prevent removal of battery Twist/lock mounting bracket for installation Power up, malfunction, and end of life indication Requires one 3-volt lithium battery Plastic White Measures 5-3/4" diameter x 1-1/4" H Weighs 0.5 lb. UL listed 10-year manufacturer's warranty Model PRC710V SKU # 45553059