Now in stock!!! 3/4" thick 4'x8' sheets and 3/4" thick 2'x16' sheets. Extira panels may look like MDF, but they don’t perform like it. Different ingredients and a patented and proprietary manufacturing process lead to a superior performance. Extira is easy to work with; can be carved, routed and machined. Resists moisture, rot, and termites. Twice as strong as MDF, Extira is made to be used outside. Extira has a 10-year warranty.