FX-4 Carbon Monoxide Alarm Marine Use - Low Voltage Hard Wired Alarm. Replaces your CO alarms that are over 5 years old. No Bags. No Tags. Full 5-Year service life, longer than CO Sentinel CMD-4M alarms. CMD-4M and CMD-3M that have reached end of life.  Features: * Conforms To ANSI / UL STD 2034 - Marine * Meets ABYC A-24. NMMA Listed Component * Most Reliable * Boats DC electrical system or marine grade batteries supply power to the alarm * No missing or dead batteries to replace * Proven Sensing Technology * Prevents nuisance alarms which could lead to confusion and disconnected detectors * Advanced Technology * Alarm Mute button with advanced technology that silences alarm while boat is ventilated * Rapid recovery sensor resets when silenced or reactivates alarm if dangerous levels of CO remain * Loud. 85 dB alarm alerts you to CO danger * Case Size: 2.5”W x 3.5”H x 1.25”D