Kidde 900-0102-02 Battery Operated Carbon Monoxide And Smoke Alarm, 85 DB At 10 FT Loud, 40 - 100 DEG F Operating, Environmental Conditions: 5 - 95 PCT Relative Humidity (RH), Smoke: Ionization, Carbon Monoxide: Electrochemical Sensor, Dimensions: 5-3/4 IN Diameter X 1.7 IN Depth, Flashing LED Displ