This Kidde 10-Year carbon monoxide detector is easy to install and alerts your family when elevated carbon monoxide levels are detected in your home. Carbon monoxide alarms should be placed outside each sleeping area and on every level of the home. Additional CO alarms are recommended 5-20 ft from sources of CO such as a furnace, water heater, or fireplace. This alarm is powered by a 10-Year sealed-in, non-replaceable lithium ion battery. No hardwire installation required and no need to change the batteries over the 10-year life of the alarm. Simply replace the entire unit after 10 years.