Guitar Neck Straight Edge (Notched) Luthiers Tool Designed to check guitar neck straightness of the fretboard and not just the frets. One side is for 25.5" (Fender) scale guitars, and the other side is for 24.75 (Gibson) scale guitars. Works with most electric guitars 6061 Aluminium- Nice Brushed Finish Machined Edges for Flatness / Cheaper Tools Ae Not