The package includes 10 Guitar Neck Notched String Measurement Ruler and 10 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 design, works well with most guitar, specially suits for (24.75 inch ) and for (25.5 inch ) electric guitars Ruler - 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 Excellent Luthier tool and essential for any guitar technician, or guitarist who wants to look after, maintain and repair their instrument themselves. Specifications Guitar Neck Ruler : Item Size: 41.8 x 3.7 x 0.4cm / 16.5 x 1.5 x 0.15inch Suits for (24.75 inch ) and for (25.5 inch ) electric guitars String Action Gauge Ruler: Size: . 8.5 x 5.4cm / 3.3 x 2.1inch color:silver Material: Stainless Steel Package Contents: 10 x Guitar Neck Straight Edge ruler 10 x Ruler Only the above package content, other products are not included. Note: Light reflection 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.