120v, ac/dc, hardwired carbon monoxide alarm, with 9v battery back up, electrochemical carbon monoxide sensor, latching alarm indicator, 2 silence features, intelligent sensing technology, dust cover, easy installation/maintenance, end of life signal, single button test/silence, meets codes where carbon monoxide alarms are required for new construction, 10 year carbon monoxide sensor, 10year end of life, 10 year limited warranty.