Being able to measure your fretboard and string radius is a critical step in the setup process. MusicNomad's precision Radius Gauge is packed with features and benefits. The accurate measurements (7.25��, 9.5��, 10��, 12��, 14��, 15��, 16��, 20��) and easy-to-follow instructions on the gauge give you the confidence to get the job done right. The premium stainless steel with polished smooth edges combined with laser-etched numbers and text ensures years of use.