The premium fretboard protectors are manufactured using a high-precision process that produces a very smooth finish on the high-quality stainless steel material, which is non-magnetic, corrosion-resistant, and heat-resistant. The specially designed curved angle helps it fit on each fret. The innovative ergonomic handle makes each fret care task easier, faster, and prevents your fingers from getting in the way. The set of 3 GRIP Guards works on all string instruments and includes 1 for each size (small, medium, and jumbo) of frets. Their ideal width allows you to work up and down on any fretboard whether on a guitar, bass, or even a ukulele.