A device for detecting the “Silent Killer”, Carbon Monoxide, which is released when fuels are burnt inefficiently. Raising loud 85db alarm and flashing RED LED light to alert when detecting the CO in the room. This alarm can be mounted on the ceiling or on a wall near the ceiling. Battery operated, five year lifetime, and chirp sounds and indicator light notify you the end of battery lifetime. This alarm comes with calibrated test gas kit to enable the unit to be inclusively tested on installation and annually over the expected life. Certified to BS EN 50291. Battery included. Hard wire version is also available.