Each plug-in carbon monoxide alarm with a sealed 10-year battery warranty is intended to detect smoke from buildings and operates in 4.4 Degrees C to 37.8 Degrees C temperatures. This alarm measures 9.4 width x 15.7 height x 12 centimetres diameter and 4.5 centimetres deep. It comes with a digital display, peak level memory, a test/reset button, and a nine-volt battery backup.