Super-smooth frets with your rotary tool! Rubberized ceramic wheels give your fret jobs that mirror shine and ultra-smooth feel players love. Much faster and easier than hand polishing, the complete set includes fine and extra-fine wheels (5 each), with a 1/8"-shank mandrel. Mount the wheel and mandrel in your rotary tool. Lightly groove the edge of the wheel with a small round file. The slim handpiece makes it easy to hold the grooved wheel on a crowned fret, to gently polish it to a smooth shine.