The diagnosis of the level of the frets and the fretboard is easier with the Tri-Beam Straight Edge Ruler by MusicNomad. The unique 3-level triangular design provides 3 critical lengths: 17.6" (44.7cm), 12" (30.5cm), and 6.5" (16.5cm) for isolating and identifying problems with the frets and fretboard. Made from high-quality aluminum, it ensures alignment across the entire length and features polished, smooth edges. It comes with SAE and metric ruler markings, as well as 13 popular guitar and bass fret scale lengths. It also includes a hanging hole.