Designed for professional luthiers to crown and shape those flattened out frets, for half the price of a crowning file. This tool has a Diamond Abrasive Coating bonded into the tool done professionally. NOT just diamond sand paper glued on! This tool will give you years of service. Will work on all fret sizes, jumbo, and bass frets. After you have leveled your frets, simply use this tool across the frets until the desired roundness is achieved. This tool is 4″ long with a .14 diameter slot of 400 (very fine) grit Diamond Coating that will shape, but remove any scratches from the leveling process. Optional polishing will only require some steel wool. Dimensions: ½ dia. X 4″Long. Works perfect with our Fret Leveling Sanding Board. You will save time from using a traditional file and have a more consistent rounded shape with every fret. It is also available in combination sets with our other fret finishing tools. Because of the round shape, there is plenty of clearance on the sides so not to scratch your freeboard. Masking the freeboard with tape maybe optional. Use to touch up nicked frets before putting on new strings. This tool is smooth on the frets and will not leave marks as files do.