Kidde 0916E Battery Operated Smoke Alarm With Hush, 85 DB At 10 FT Loud, 9 VDC Operating, 40 - 100 Deg F Operating, Environmental Conditions: Up to 85 PCT Relative Humidity (RH), Ionization Sensor, Dimensions: 5 In Diameter X 1-1/2 In Depth, Flashing Led Display, Mounting: Wall or Ceiling, Sensitivity: 0.64 - 1.35 PCT/FT, Ul Listed