IRWIN Tools Carpenter Square, Aluminum, 16-Inch by 24-Inch (1794450) Permanent deep carpenter square stampings for durability Durable, rust-proof aluminum body Carpenter hand tools for laying out and marking angles in framing, roofing and stairway work Also used for checking squareness and flatness Dimensions: 16" x 24" Permanent deep carpenter square stampings for durability Durable, rust-proof aluminum body Carpenter hand tools for laying out and marking angles in framing, roofing and stairway work Also used for checking squareness and flatness Dimensions: 16" x 24"