3 Kinds of guitar repair tool: All the gauges are in different scales for satisfying your diversified needs, you can use them to measure your guitar according to your own requirements. Metric and imperial marking all in one, which is very useful for people not skilled in metric/imperial conversion. A great combination of measuring tools for electric guitar, acoustic guitar, bass, banjo and folk guitar, etc. Specifications: Material: stainless steel Guitar neck ruler : Application: Good for synthesized 25.5 inch and 24.75 inch scale guitar or other 6 string instruments. String action gauge ruler: Application: measuring string height, frets, nuts, saddle, and other parts of a guitar. Fret rocker: Application: the fret rocker can span over 3 frets and can check if frets are on the same level Package includes: 1 x Guitar neck notched straight edge luthiers tool 1 x Fret rocker 1 x String action ruler