Kidde 21006377 Wire-In Carbon Monoxide And Smoke Alarm With Battery Backup, 85 DB At 10 FT Loud, 60 HZ Operating Frequency, 120 VAC Operating, 25 MILAMP Operating, 40 - 100 DEG F Operating, Environmental Conditions: 5 - 95 PCT Relative Humidity (RH), Smoke: Ionization, Carbon Monoxide: Electrochemic