Features: Material: Made of steel with a lubricious coating to prevent rust. There are 9 kinds of gauge of different sizes:7.25"9.5" 10"12"14"15"16"17"20". The blade feeler is a guitar universal pitch chord measuring tool with chrome-plated spindle, easy to clean and professional look. Easy to identify: double-marked , the size is etched into a feeler gauge for easy identification. Can be used to measure a variety of electric guitars, electric bass, acoustic guitar, acoustic guitar, electric guitar fingerboard in arc measurement, curvature to adjust the string bridge. Specification: Measuring Size:7.25 "9.5" 10 "12" 14 "15" 16 "17" 20 " Package List: 1 x Guitar Feeler Gauge 9 x Radius Gauge 1、Material: Made of steel with a lubricious coating to prevent rust. 2、There are 9 kinds of gauge of different sizes:7.25 3、The blade feeler is a guitar universal pitch chord measuring tool with chrome-plated spindle, easy to clean and professional look. 4、Easy to identify: double-marked , the size is etched into a feeler gauge for easy identification. 5、Can be used to measure a variety of electric guitars, electric bass, acoustic guitar, acoustic guitar, electric guitar fingerboard in arc measurement, curvature to adjust the string bridge.