Basic plug-in CO alarm. Electrochemical Carbon Monoxide Sensor - the most accurate sensor available as compared to other sensing technologies Single Button Test/Silence Silence feature - temporarily silence an unwanted nuisance alarm End of Life Signal provides audible notification alarms needs to be replaced 7-Years Limited Warranty Model # CO600B Weight 4.0 oz Dimension 3.3"H x 4.8"L x 1.5"D Operating Voltage 120V AC 60 Hz Temperature Range 40°F (4°C) to 100°F (38°C) Humidity Range 10% to 95% relative humidity (RH) Audio Alarm 85dB at 10 feet Test/Silence Electronically simulates CO conditions, causing the unit to alarm or temporarily silence the alarm Alarm Reset Automatic when carbon monoxide clears CO Sensor Electrochemical Indicator Lights/Sounds AC Power: Constant red light Audio Alarm (4 beeps, pause, 4 beeps), rapidly flashing red light Listing Listed to UL 2034 Standard