DMT Mini-Sharp® portable diamond sharpener.Diamond Mini-Sharp Sharpener - a Diamond Whetstone that travels with you. Folding handle protects the stone when not in use. Lightweight and ultra portable. Extra-Coarse diamond (60 micron / 220 mesh) when significant removal of material is needed for a damaged edge. Lightweight and ultra portable, handy key chain swivel ring for your keys or attach to zipper pulls or backpacks. Handy size: 5 1/2" (140mm) opened. Size of stone: 2 11/16" x 15/16" x 3/16" (70mm x 25mm x 4mm). Sharpening with diamonds is fast and easy. No messy oils needed-sharpen dry or with water. Ultra portable, key chain sharpener for fishhooks too. Sharpens knives faster than conventional stones with DMT's monocrystalline diamond surface. No oil is needed-sharpen dry or with water. Durable construction will provide years of consistent performance and reliable service. Made in USA.