This unique tool is actually five tools in one: a tri-square, a miter square, a protractor, a line scriber, and a saw guide. 1/4" spaced notches to facilitate scribing lines. Includes markings for Swanson's® One-Number Method™ of rafter layout, and is packaged with the Swanson® Blue Book of Rafter Length and Roof Construction. Includes the new Diamond™ feature that makes layout work and seat cuts on common rafters easy. Black filled markings and blue book.