1.High Quality - Made of stainless steel with rounded off edge, anti rust, prevent scratch or cutting, and long service life2.Wide Usage - Suitable for measure all kinds of electric guitar, electric bass, acoustic guitar, electric box guitar fretboard measured in radians, radians to adjust the strings piano code3.It is a guitar common spacing chord distance measure tool, chrome plated main shaft for easy clean up and professional look4.Can be applied to accurately measure fret board radius, saddle radius nut radius from either the top or the bottom radius , a must have for bass guitar maintain and adjustment5.String Action Ruler - Each gauge is printed with a useful decimal and metric conversion chart. Provides precise and accurate measurements not only for string action, but can also be used in measuring nut height, string to pole distance and fret slot depthProduct name: Guitar T-shaped arc ruler, string height rulercolour: silverMaterial: Stainless Steel + PlasticPackage Contents:9 x radian ruler1 x string height rulerOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.