Handle (utilized as holder to store diamond stone inside) has Non-Slip Finger Grip surface on body and chuck nut to aid in removing or replacing sharpening stone and for more positive control during tool use. Diamond stone has flat side for sharpening standard knives, round side for sharpening serrated knives, "V" groove for sharpening fishhooks, darts and arrows or all sides may be used for filing. Simply loosen built-in chuck, slide out diamond stone and tighten chuck nut. All machined parts are plated or made of materials to help prevent rust & corrosion. Handles & Holders Made In USA. Diamond stones imported from other countries. (Des.Pat.No. D416,777) >>> SUGGESTED USES: SHARPEN Knives, Scissors, Kitchen Utensils, Fishhooks, Darts, Hunting Arrows, Garden Tools, Router Bits, Shop Tools, Camping Tools, Ice Skates - UTILITY FILE for model making, shaping metal or wood, Fingernail File, deburring & removing sharp edges