The package includes 1 Guitar Neck Notched String Measurement Ruler and 1 String Action Ruler. Perfect accurate action measurements for string instruments such as guitar, bass, mandolin, banjo, etc.Guitar Neck Notched Straight Ruler - Made of stainless steel, rustproof, sturdy enough for your long-term use. Size: 16.5 x 1.45 x 0.15 inch, Dual scale , works with most guitar, specially suits for (24.75 inch ) and for (25.5 inch ) electric guitarsRuler - Made of high quality plastic, The ruler is double-sided, there is fraction, decimal, metric conversion chart on back.This guitar string action gauge ruler can measure string height, bridge saddle height, saddle slot depth, fret slot depth and nut height and accurately measure other setup adjustments.The Neck Notched String Measurement Ruler is designed to check guitar neck straightness of the fretboard and frets. Ruler Use To Measure: Nut / String / Bridge / Pickup Pole Piece / Saddle Height Plus Saddle Slot/ Fret Slot Depths Luthier tool and for any guitar technician, or guitarist who wants to look after, maintain and repair their instrument themselves.SpecificationsGuitar Neck Ruler :Item Size: 41.8 * 3.7 * 0.4cm / 16.5 * 1.5 * 0.15inchSuits for (24.75 inch ) and for (25.5 inch ) electric guitarsString Action Gauge Ruler:Size: . 8.5 x 5.4cm / 3.3 x 2.1inchcolor:silverMaterial: Stainless SteelPackage Contents:1 * Guitar Neck Straight Edge ruler1 * RulerOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.