**Radius Gauges**: - **Function**: Quickly determine the curvature of a fingerboard or bridge. Useful for checking work while smoothing or shaping fingerboards or frets to prevent accidental shape alteration. - **Purchase Options**: Sold individually or as a set of 6, with savings when buying the set. - **Importance for Guitars**: Essential for guitars with compound radius (curvature changes from nut to end of fingerboard) as it's difficult to visually assess the change. Also used for profiling acoustic bridge saddles and setting string heights on electric guitar bridges. - **Specifications**: Precision laser-cut with radii of 7-1/4", 9-1/2", 10", 12", 14", 15", 16" and 20". Made of steel for durability, suitable for string spreads and fingerboards up to 3-1/4" (82.55mm) wide. - **Combined Use**: Can be used with Radiused Leveling Blocks for professional results. - **Notched Gauges**: New version allows checking fingerboards without removing strings. Has closely-spaced notches near the nut and wider spacing near the body (ideal for compound radius fingerboards), with the same radii as the regular set.