Shapers Layout Square with Fin Placement Measurements. Clear Poly-carbonate 'transparent' sheet which sits flat on surfboard blank. Giving accurate center-finding measurements from stringer to rail. Inches and MM Measurements. Measure Nose, tail and Midpoint exactly with the printed measurements on the square. Quick layout for Fin Positioning. Also used for tail measurements and fin settings. The Shapers Layout Square - Dims: 24" in width | 609mm, 12" in Height | 304mm