The Sheet Metal Wall Plate is a 16″ x 16″ galvanized 24 gauge sheet metal plate with an oval hole in the center. This item is useful when using a stove indoors to protect surfaces behind the stove. The hole is cut to fit the #3 section of nesting stovepipe on approximately a 45 degree angle. To fit the sheet metal wall plate you will need to cut a 14″ x 14″ square hole in the wall and mount the plate with screws (included) on the outside of the wall. This is for single walls only and can be used in a window if screen is replaced with plywood.