USCG approved. Heat activated discharge is automatic at 165° F, 74° C. A control panel indicator lamp and pressure gauge provide charge/discharge system status. Uses FE-241 fire suppression agents. Selecting your system: determine the volume of your engine compartment in cubic feet at the keel ( L x W x D), choose the model that meets or exceeds your engine compartment volume. Diesel powered craft must also install the automatic engine shutdown system.