Grobet 6" INOX Half-Round File, Cut 0, Item No. 30.231V High & Heavy 25 Spring rings clasps that

25 Spring rings clasps that measure approximately 9 mm (3/8") in diameter

This is the best case opener I have ever tried

and other soft materials

4 mm in diameter and have an Iso of 014

Grobet 6" INOX Half-Round File, Cut 0, Item No. 30.231V High & Heavy 25 Spring rings clasps thatGrobet INOX Swiss Pattern Precision Files, know as "The File with the Yellow Tang". With Rockwell hardness 72HRc 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.