Space saving compact design for boats. Designed for the harsh marine environment. No False Alarms due to new boat smell, outgassing or non-hazardous levels of hydrocarbon gases encountered while boating. Alarm Mute button silences alarm while boat is ventilated. Rapid recovery sensor resets when silenced or reactivates alarm if dangerous levels of CO remain. Memory Scan - Retains the CO level that activated the alarm. Micro Current Technology - Saves precious battery power in a boat. End of Life Signal alerts boater to replace the alarm after 5 years of service. Listed to UL 2034 Marine Use and CSA 6.19-01.