First Alert ONELINK enabled smoke and carbon monoxide alarms. They automatically communicate with other ONELINK enabled alarms when installed creating a wireless safety network. Features include voice alarm with programmable location. Programmable with up to 11 locations (such as kitchen ). When alarm sounds a voice will tell you the location of unit if smoke or carbon monoxide is detected. Photoelectric smoke alarm reduces nuisance alarms. Alarm and low battery silence feature. Includes 2 "AA" batteries. Vermont and Oregon approved.