Each of these .010" x 3-1/8" x 7/8" stainless steel masks fits over a fret, to protect the fingerboard while you file or polish the fret. Universal size, they can be bent for any fingerboard width or curvature, taped down, or held by hand. It's a simple idea for a clean professional fret job!
Dan Erlewine's Fretting Series
Complete instruction from fret basics like installation and dressing, through complex refrets and fretting for the production shop.