ToolUSA Toolusa Deluxe Trio Of 2", 4" & 6" Machinist Squares: KIT-TJ4404W 2-Inch and 6-inch squares are made of fully grounded sturdy and polished carbon steel construction 4 inch square is made of durable wood and metal construction Exact 90 degree angles for checking squareness of work piece - sometimes you just have to know! Accurate and professional quality - should last you a very long time Small enough set to fit in most tool boxes so you can carry them on the go