Parallel ruler 12” Alvin rolling parallel ruler 312 is a multipurpose drafting tool. The Alvin parallel ruler lets you measure in inches and centimeters and draw quadrants, squares, circles, angles, crosshatching, and vertical and horizontal parallel lines, quickly and easily. This 12” parallel ruler is excellent for making parallel lines. The Rolling parallel ruler functions as a compass, horizontal ruler, straightedge, protractor, circle template and angle template, all in one. The parallel rulers unique compass pivot button eliminates surface marking. Individually packaged with instructions on box back, ideal for artists, students, pattern-makers, and designers the Alvin 12” rolling parallel ruler.