Best Seller | First Alert Carbon Monoxide Detector in Black | 9.45 H x 6.95 W x 4.15 D in | Wayfair 1039741 The 2-pack First Alert carbon monoxide alarm utilizes an electrochemical carbon monoxide sensor to detect carbon monoxide. The battery-powered design of this personal carbon monoxide detector means your space can be monitored for dangerous carbon... more | | $49.81 FREE shipping go to store |