This FireAngel ECO 1 year carbon monoxide alarm is specifically designed with a compact and aesthetically pleasing design that will look good in your home. The alarm uses an advanced electrochemical sensor, designed to accurately measure low levels of carbon monoxise. This provides an early warning of deadly levels. Also features a large easy press test and reset button which makes weekly testing of alarm simple and easy. Other features include a dual LED display with green light, indicating alarm is correctly functioning providing peace of mind.