Guide for fretting made in stainless steel, with two detachable 0.3mm thickness silicon rubber sheet to grip a fingerboard to prevent slipping. (We recommend to use a clamp and in this case, remove upper silicon sheet). 3 Neodymium magnets backed Polyacetat guide draws the saw blade and support the cutting straightly and at right angle to the fingerboard. The magnets keep the saw straight and the blocking piece retains the saw back and avoids sawing too deep. The saw guide allows you to control the depth while sawing. Depth can be adjusted by moving the central piece along the slide. Slide frame side has scale marks. 1 scale mark means 1mm depth adjustment. Fret slot depth can be controlled from 0.3mm - 5.3mm.