Use this low-profile Fireboy-Xintex CO Sentinel CARBON MONOXIDE ALARM on marine equipment. Once it detects dangerously high CO levels the alarm sounds and it shuts down the generators automatically. If multiple alarms are connected they will all sound. Controlled by a microprocessor, the alarm's time-weighted average carbon monoxide measurement process constantly monitors all CO levels, eliminating most false alarms. Made of durable polypropylene and listed to UL 2034 Marine Standards. Measures 4 1/4"L x 2 3/4"W x 1 3/4"D.