Safe-T-Alert 62 Series Carbon Monoxide Alarm - 24V Flush Mount - Black w/Relay [62-542-R-BL-24V]62 Series Carbon Monoxide Alarm 24V Flush Mount Black with Relay Features: NMMA Listed Component. Space saving design works in a harsh marine environment. Works in extreme temperatures. Only marine CO alarm listed to operational temperatures of 40F to 158F. Alarm has consistently held up in the excessive cold and heat due to high quality sensor. No False Alarms due to new boat smell, outgassing, or non hazardous levels of hydrocarbon gases encountered