1、WIDE APPLICATION: Guitar notched radius gauge fingerboard is compatible with string instruments, such as guitar, bass, banjo, ukulele, mandolin, etc. 2、PORTABLE AND ACCURATE: Guitar notched radius gauge is light and portable, you can put in your pocket and carry with you. Quickly and accurately find the curvature of a fingerboard or bridge with these radius gauges 3、CLEAR SCALE: Guitar notched radius gauge fingerboard is made of excellent stainless steel with accurate engraving and complete and clear scales. You can accurately measure and set your guitar 4、VARIOUS RADIUS: The package come with two narrow radius gauges and two wide radius gauges in 7.25in, 9.5in, 10in, 12in, 14in, 15in, 16in, 20in radius 5、APPLICABLE SCENARIO: Guitar notched radius gauges can be used to measure the string distance, bridge saddle height and depth, fret groove depth. The edge of the measuring ruler is carefully polished and polished, so you can use at any time without worrying about scratching your fingers