This Johnson 48 in. Aluminum Drywall T-Square is perfect for general carpentry use, such as marking cut lines on sheets of plywood, OSB, drywall and other board materials. Built to last from extruded aluminum with an anodized finish, it features screened, thermal-bonded 1/8 in. graduations in black that are easy to read. Solid, 4-rivet construction securely bonds the head to the blade.. Extruded aluminum blade and head with anodized finish for durability. Solid 4-rivet construction maintains a secure bond between head and blade. Great for marking cut lines on sheets of plywood, OSB, drywall and other board materials. Note: product may vary by store. Screened, thermal-bonded graduations in black are boldly visible. 1/8 in. graduations are easy to read