Kidde 21006406 Interconnectable Wire-In Carbon Monoxide Alarm With Battery Backup, 85 DB At 10 FT Loud, 60 HZ Operating Frequency, 120 Vac Operating, 40 - 100 Deg F Operating, Environmental Conditions: 5 - 95 PCT Relative Humidity (RH), Electrochemical Sensor, Dimensions: 5-3/4 In Diameter X 1.8 In Depth, Led Display, Mounting: Wall or Ceiling, Included: 9 V Alkaline Battery, Multiple Contractor, Ul 2034, Article 760 Of The National Electric Code and Nfpa 72