USAGE RANGE this tool set is suitable for measuring all kinds of electric acoustic guitar, electric bass, electric box guitar fretboard that measured in radians to adjust the strings piano code. GUITAR BRIDGE SADDLE NUT FILES: 1.Made of high-quality steels, perfect tools filing string slots into nut and bridge. 2.With 0.4mm / 0.5mm / 0.6mm / 0.7mm / 0.75mm / 0.8mm / 0.9mm / 1.0mm / 1.05 mm / 1.1mm / 1.2mm / 1.4mm / 1.6 mm different size, 25mm grinding length and 30mm length of the hilt. 3.These -shaft files are easier to use than the shorter ones commonly available improvement stores 9PCS RADIUS GAUGE: Color: silver Material: Stainless steel 1 x 9 understring radius gauges ( 7.25, 9.5, 10, 12, 14, 15, 16, 17and 20) STRING ACTION GAUGE RULER: String ruler side: Material: plastic Size: 55mmx90mmx1mm Weight: about 10g Graduations displayed: mm and inches Measuring string height, frets, nuts, saddle, and other parts of a guitar Holding this card to the strings, you can visually find the suitable string height. ruler side: Could be used for gut guitars, electric guitars (raise or lower string height), acoustic guitars, and bass guitars (including six string bass guitars) to adjust space. Package Contents: 1 x 9PCS RADIUS GAUGE 1 x STRING ACTION GAUGE RULER 1 x GUITAR BRIDGE SADDLE NUT FILES 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.