This high-quality knee brace is made from durable 20ga. galvanized steel and is designed to provide reliable support for your carport structure. Offered in three sizes. Outside dimensions are 24"x2-3/4", 36"x2-3/4" or 48"x2-3/4". Inside opening is 2-1/2". Four holes are predrilled to accommodate a #12 screw to assist in easy installation. Perfect for those in need of a reliable solution to keep their carport in top condition. Installation hardware not included.