Studry material: the fret rocker and notched straight edge are made of stainless steel, sturdy enough for your long-term use and not easy to scratch your guitars 9 understring radius gauge: stainless steel material, set of 9 including: 7.25 inch, 9.5 inch, 10 inch, 12 inch, 14 inch, 15 inch, 16 inch, 17 inch and 20 inch radius, luthier tools for Guitar and Bass Setup Usage: these guitar luthier tools are good gifts to guitar technicians and guitarists to maintain and repair their instrument themselves in a short time, reducing buzzing; Good tools for electric guitar, acoustic guitar, bass, banjo and folk guitar, etc. size: 55*90mm Material:stainless steel colour:Silver Package Contents: 1 * notched ruler 1 * space ruler 1 * Triple-cornered ruler 9 * Understring Radius Gauge Only 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.