Excellent luthier tool, essential for any guitar technician or guitarist who wants to take care of, maintain and repair their instrument themselves. Package includes 1 Guitar Neck Notch String Measuring Ruler and 1 String Action Ruler. Perfect and accurate measurement of stringed instruments, such as guitar, bass, mandolin, banjo, etc. Guitar Neck Notch Ruler Made of stainless steel, rustproof, strong enough for longterm use. Size: 16.5 x 1.45 x 0.13 inches, Weight: 230 grams. Dual scale design, suitable for most guitars, especially for Gibson (24.75") and (25.5") electric guitars Fritz Ruler Made of highquality plastic, the ruler is doublesided with fraction, decimal, metric conversion chart on the back. This guitar string action ruler can measure string height, saddle height, saddle groove depth, wire groove depth and nut height, and accurately measure other setting adjustments. Neck Notch String Measuring Ruler is used to check guitar neck straightness to fingerboard and strings. Fritz Ruler measures: Nut/Rope/Bridge/Pickup Rod/Saddle Height plus Saddle Groove/Wire Groove Depth