The Lufkin Rule Co. 6 Inch Double Square is a high-quality metalworking inspection and measurement tool made of steel. This ruler features a 6-inch blade length with a 4R graduation style and a base length of 3.5 inches. Proudly made in the United States, this double square is a reliable and durable tool for precision measurements in various industrial and manufacturing applications. The inclusion of a 41' and 59' rule adds versatility to this essential tool for professionals in the field.