54193 DIAMOND KNIFE SHARPENING STONE 3/4" x 4" . •Have all your favorite knives & scissors cutting like new with this easy to use sharpening stone •Solid steel block has industrial diamond permanently brazed to surface during manufacture •Hardest abrasive material available works with any metal, even hardened stainless steel & carbide •Easy to handle and store 4" x 3/4"; fits in pocket, tackle box or toolbox drawer •Extra-fine 600 grit hones to razor-blade sharpness; use wet or dry Knife blades dull because as each cut is made, microscopic deformities and deviations occur on the metal at the very edge where the two sides, called grinds, form the cutting edge. Over time, the accumulation of these deformities will make even the highest-quality knife seem like it can't cut warm butter. The solution is to realign the edge by filing away these tiny imperfections and the easiest method is with a diamond honing surface. Super-fine synthetic diamond particles are many-times harder than the blade metal and are extremely efficient - just a couple gentle drags across this file and you'll see a remarkable difference is knife performance. Keep one in your tackle box, hunting jacket pocket, toolbox and be sure to have one handy in the kitchen. Solid steel block with chrome finish; 4"L x 3/4"W x 1/4"D, 3.1 oz.