This is a 5/16 inch screen frame corner and constructed of stamped aluminum, and come in a milled finish. The dimensions of these corner pieces are designed to fit into the miter cut corners (at 45 degree angles) of 3/4 inch x 5/16 inch aluminum screen frames for the repair, or construction of aluminum screen frames. Using rigid corners like these provide superior strength and longevity in screen frame construction, when compared to screens assembled with plastic square-cut corner pieces that remain exposed to harsh elements. These aluminum screen frame corners are rust resistant, and assemble easily (by press-fit) without the need for any other fasteners.