Maradyne Flush Mount Marine Bus Heater Kit, 40,000 BTU, 12v, Unit Measures 16" W x 7" H x 9.6" D. Face plate 17. 62" W x 7. 5" H. Includes the following accessories: (1) 738567 MH-TA7000078 Switch Kit; (1) 739012 MH-TA00079 Wiring Harness 9'. Heater boxes are made from heavy-duty, glass-filled nylon and will not corrode. Inner wall strengthening plates threaded with 1/4-20 weld nuts. 5/8" hose barbs, 12 volt 3-speed fan, 5-12 amp draw. Tested to SAE J1171 and ISO 8846. Meets USCG requirements for ignition protection. All hardware is marine grade. This uses 5/8" water hear hose to connect to coolant system. Use part# HMH-160-06250