Kidde 21006371 Firex Smoke Alarm With Battery Backup, 85 DB At 10 FT Loud, 60 HZ Operating Frequency, 120 VAC Operating, 80 MILAMP Operating, 40 - 100 DEG F Operating, Environmental Conditions: 5 - 95 PCT Relative Humidity (RH), Photoelectric Sensor, Dimensions: 5.6 IN Diameter X 1.55 IN Depth, Flas