12″x42″x 1″ return (3 1/2 sq ft. approximately). Next generation panels with a raised ribbed back to allow for airflow and drainage, the manufactured corner is already constructed, for a cleaner and more efficient installation. Designed to be installed from left to right, and bottom to top. To be installed with non corrosive deck screws. Minimum of 7 screws around the flange and 2 through the face (between the stone pattern.) smaller size for a more random pattern. There is 1 and 4 pattern repeat in all of the Faux Stone product lines. It is recommended to use 1 left and 1 Right corner panel for every 2 feet of corner.