The Big 12 is seven tools in one: a framing square, try square, miter square, protractor, saw guide, stair gauge and out-of-square corner angle finder. Its constructed of heavy-gauge aluminum alloy and includes the Layout Bar for use in determining out-of-square corners. Also included are the Swanson Blue Book for roof and stairway layout and Layout Bar with hardware.
See how to LAY-OUT STAIRS
See how to fix OUT-OF-SQUARE CORNERS

Features
Heavy gauge aluminum alloy

Matte finish to prevent glare

1/4 in. and 1/2 in. spaced notches to facilitate scribing lines

Black gradations for easy reading

Patented Layout Bar

Great for deck framing and stairway building!