Quickly find the curvature of a fingerboard or bridge with this set of radius gauges. Use these gauges frequently to check your work as you smooth or shape a fingerboard or frets: a quick visual check keeps you from accidentally altering the shape — a mistake that's easy to make and hard to fix. Guitars commonly have a "compound radius," meaning the curvature changes from the nut to the end of the fingerboard. "Eyeballing" this subtle change is next to impossible; that's why a set of radius gauges is essential. Also use them for profiling an acoustic bridge saddle and setting the string heights on an electric guitar bridge. Our gauges have precision laser-cut 7-1/4", 9-1/2", 10", 12", 14", 15", 16" and 20" radii. They're made of stainless steel for durability in the busy shop. These gauges work for string spreads and fingerboards up to 3-1/4" (82.55mm) wide. Use them in combination with radiused leveling blocks for professional results. This set includes 2 laser-cut gauges, each with 4 different radii: 1 gauge with 7-1/4", 9-1/2", 10" and 12" radii 1 gauge with 14", 15", 16" and 20" radii