Graootoly 4Pack Acrylic Guitar Notched Radius Gauges Fingerboard Guitar Ruler Fretboard Measuring Tool for Acoustic Guitar

Material: Made of Acrylic so it is stable, and widely used., convenient, pocket-sized measuring tool. Size: 4pcs includes gauges in 7.25inch, 9.5inch, 10inch, 12inch, 14inch, 15inch, 16inch, 20 inch . Portable: when you to check a fingerboard without taking the strings off.It's to use than any ruler, and stays parallel to the fingerboard-much easier than trying to hold a ruler perpendicular to a rounded fret. Applies to:7.25inch for electric guitars with a relatively arc or ukulele 9.5inch for electric guitars;10inch for electric guitar;12/14/16inch for acoustic guitar;18/20inch for classical guitars,Fit for string instruments such as electronic guitar, , acoustic guitar, mandolin, etc.