For the detection of carbon monoxide in private houses and flats, households that use gas heating or charcoal fireplaces, kitchens with gas cookers, garden sheds, or rooms heated with a mushroom heater or gas cartridge. The alarm activates at a gas quantity of 30 ppm. The sensor has a service life of 10 years and features both optical and acoustic alarms (85 dB at 3 meters). It includes three Mignon AA batteries and wall mounting, as well as a test button and LCD operating display.