FIRST ALERT series of wireless talking battery operated smoke and CO alarms effectively eliminates the need for a wired connection and operates entirely on batteries. The latest advancement in a series celebrated for its intuitive use of technology, the first alert wireless interconnect collection offers an abundance of options when it comes to creating the ideal safety network. Wirelessly inter-connectivity allows you to connect up to 16 alarms within your home! Voice can easily be programmed for alarm's location within your home. (this feature comes with 11 pre-programmed choices) Voice also notifies which hazard is being detected. If the alarm set in your kitchen senses smoke, all of your first alert wireless interconnect alarms will announce 'Warning, evacuate! Smoke in the Kitchen!'. This feature allows for the maximum in whole home protection. first alert wireless interconnect talking battery operated smoke and CO alarms utilize an electrochemical sensor that allows for optimal efficiency in detecting carbon monoxide. The realization of photoelectric smoke sensing technology will effectively reduce the number of nuisance alarms triggered by cooking smoke and shower steam. This alarm comes equipped with a mute button that serves the dual purpose of quickly silencing your alarm as well as testing its function. The combination of an end of life timer and an increased emphasis on the unit's 85 db sound output establishes peace of mind, while the inclusion of dual smoke and carbon monoxide sensing all but guarantees the safest of experiences.