DESC: Kidde Digital Carbon Monoxide Alarm Direct Wire - Interconnectable The Kidde 900-0121 is an AC wire-in carbon monoxide alarm that protects you and your family from the dangers of carbon monoxide. The digital display allows for continuous monitoring of carbon monoxide levels. Its multiple contractor friendly features ensure easy installation and minimal troubleshooting. This alarm interconnects with up to 24 Kidde devices to the devices including smoke alarms, CO alarms and heat alarms, on one wiring network. Then 900- 0121 includes a 9V battery back up for continuous protection in case of power failure along with a five year limited warranty. The Kidde 900-0121 is an essential device designed to protect you and your family from the dangers of carbon monoxide in your home. The digital display features allows constant monitoring of carbon monoxide levels and updates every 15 seconds to let you know if levels change. The peak level memory feature displays the highest