Fireboy S-2A combination propane and compressed natural gas monitor and controller for vessels. Monitor features include low current draw, plug-in sensors (second sensor optional), display module fault light, alarm and fault light, and alarm to indicate a malfunction in either one of the sensors. (Fault indicators show that the module or sensors are not working and may need repair.)

MS-2 sensor and 1 SV-1 solenoid valve included.

The system is calibrated at 20 percent LEL (lower explosive limit) to eliminate most nuisance alarms while allowing enough time to take action.