Cozy C355 Gravity Single-Sided Furnace 35K BTU Cozy Gravity Wall Furnaces mount on any inside or outside wall with 16" center stud space and provide both circulated and radiated heat – a preferred combination! It provides economy and flexibility of operation and allow individual temperature control in “hard-to-heat” areas. Cozy is a perfect answer for either new construction or remodeling heating applications. Specifications: Type Gas Natural with 1/2 inch gas inletBTU Input per hour 35,000 Vent Pipe Opening 4"Finished Dimensions: 16-1/2" W x 68-3/8" H x 6-1/2" D*Model W355G replaces model W355F