Carbon Monoxide (CO) is a toxic, odorless, and tasteless gas produced by the incomplete combustion of gasoline, kerosene, natural gas, butane, propane, fuel oil, wood, coal, and other fossil fuels. Dangerous levels of CO can be produced by internal combustion engines or from any poorly vented or improperly adjusted fuel-burning appliance. Exposure to CO may cause sickness, headaches, or even death. This Carbon Monoxide Detector can save a pilot’s life, especially when flying with the heater on, by warning of the presence of CO in the cockpit—the spot will turn gray/black when CO is in the air. The spot on the detector returns to normal color after it is exposed to fresh air. You can use this CO-DETECTOR as your personal and portable CO detection device. With the adhesive back, stick it on the panel or dash for a semi-permanent installation, or wear it on an ID badge or on a lanyard. Unopened ASA carbon monoxide detectors have a shelf life of three years. The shelf life on unopened packages has been increased to 12 months