The Swanson Tools Speed Square is an American triangular-shaped carpenters' layout out tool which combines some of the most common functions of a try square and framing square into one. It is used to make basic measurements and mark lines on dimensional lumber and may be used as a saw guide for making short 45 and 90 degree cuts. The Speed Square is 5 tools' class='desclinks'>tools in 1. Try Square Miter Square Saw Guide Line Scriber and Protractor. This kit comes with the S0101 7-inch and the T0108 Big 12-inch Speed Square. Includes 44-page Swanson Blue Book.