Norton IM200 -8" Three Stone Sharpening System - Fine India, Medium Crystolon, and Coarse Crystolon stones The Norton Crystolon and India IM313 11-1/2 inch three-stone sharpening system includes 100-grit and 150-grit silicon carbide stones and a 320-grit aluminum oxide stone, a self-contained three-stone bench sharpening unit with a lid and no-slip rubber feet, a reservoir and an angle guide. This is the best sharping system for a chef, a carpenter, a hunter or hobbist to learn how to use!