Shapers Layout Ruler is the ultimate measuring tool and a essential tool for all Shapers! Transparent polycarbonate (Strong and Flexible Plastic), sits flat on surfboard blank; Giving accurate centre-finding measurements from stringer to rail; Measurements in inches; Measure Nose, tail and Midpoint exactly with the printed measurements on the square; Quick layout for Fin Positioning; Contains locating pencil holes used for fin placements and quick center finding measurement. Also used for tail measurements and fin settings. The Shapers Layout Square - Dims 27" in width/6" in Height.