- Sturdy stainless steel construction provides durability and long service life for frequent use. - Arc measurements are engraved on the ruler to ensure precise, repeatable readings at all times. - Wide size range covers common guitar fingerboard radii: 7.25 inches, 9.5 inches, 10 inches, 12 inches, 14 inches, 15 inches, 16 inches, 17 inches, and 20 inches. This set includes all sizes you need for accurate measurements. - Accurate saddle configuration: Configure the saddles of your guitar bridge exactly to fit the radius of the finger plate, helping ensure optimal performance. - Use scenarios: - Guitar setup and intonation: Select the matching radius when installing new saddles or adjusting strings to align with the fingerboard. - Repair and luthier work: Efficiently check and adjust guitars with different radii to maintain consistent tone and intonation. - Home experimentation: Easily test and customize saddles for guitars with varying radii to find the best fit.