First Alert brand Carbon Monoxide Detection Alarm ⚠️Carbon Monoxide is an invisible, odorless and colorless gas - - it cannot be seen, smelled, or heard.. Making it extremely hazardous⚠️ ✔️9V Battery Included ✔️Easy Access Battery Door ✔️Test & Silence Button - for time efficient testing ✔️End-of-life Warning - lets you know when it's time to replace Tags Family and Home Safety Peace of Mind Holiday Newborn Baby & kids