Grobet USA INOX Precision Needle Files, know as "The File with the Yellow Tang". With Rockwell hardness 72HRc A- the hardest surface known - these files have a longer life than standard files. Highly resistant to corrosion. Little or no clogging - a simple knock removes the chips. High performance files for platinum, stainless steel, exotic plastics, and other hard to file materials. Overall length is 7" (180 mm).