MusicNomad's Tri-Beam Straightedge was designed to measure how level your frets and fingerboard with ease. Setting a new standard, Tri-Beam Straightedge's unique three-wall triangle design gives you the three critical lengths: 17.6" (44.7 cm), 12" (30.5 cm) and 6.5" (16.5 cm) to isolate and identify global or localized fret and fingerboard issues up and down the neck. Using the highest-quality aluminum and manufacturing techniques ensures straightness of the entire length and critically important polished, smooth flat edges. A big bonus, the Tri-Beam has SAE and metric ruler markings, plus 13 of the most popular guitar and bass fret scale lengths to quickly check the scale length you are working on. It even includes a convenient hang hole.