The combustion process is completely isolated from the inside of the boat by the unique, direct vent design. A built-in blower provides good heat circulation. The heater is sold with all accessories needed including a stainless steel backing plate, 28 inches of flexible double stainless chimney and the deck fitting cap. Note: A propane hose, 11″ WC regulator and fittings are needed and sold separately. Includes: A stainless steel backing plate, 28 inches of flexible double stainless chimney and Deck fitting cap. Features: Easy to install – Easy to use. Stainless Steel burner. Large ceramic glass viewing window with safety screen. Safe, direct-vent operation. Unaffected by motion or wind. Variable heat output and excellent thermal efficiency. Low fuel consumption. Compact design, with attractive appearance, made of 304 stainless steel. No interior oxygen depletion. Specifications: Overall Dimensions: 8.5″ (W) x 5.5″ (D) x 14″ (H). Heat Output: 3,200 – 4,500 BTU. Mounting Back plate: 8.375″ (W) x 0.650″ (D) x 23″ (H). Fuel Consumption: 20lb – 140 hrs. gal LOW and 20lb – 100 hrs. gal HIGH.