1. HIGH-QUALITY TWO-SIDE GRINDSTONE: the coarse grinding surface (400 grit) quickly sharpens blunt or damaged knives with just a few pulls; the fine sanding surface (grit 1000) is ideal for finishing and polishing the edges, and perfect for easy repairs to a ready sharp2. EXCELLENT SHEEPING AND GRINDING PERFORMANCE: Sharpening stone is made of professional corundum, corrosion-resistant, heat-resistant, edges and corners are clearly delineated3. 400/1000 GRINDSTONE IS SUITABLE FOR MOST GRINDING OPERATIONS: e.g. Tool steel, hardened steel, tools, knives, scissors, chisels, axes, kitchen knives, cutting class knife sharpening etc. But except serrated blades and ceramic knives etc4. WARRANTY SHARPENING WITH NON-SLIP SILICONE HOLDER: The non-slip silicone holder holds the sharpening stone securely in place, so you never have to worry about slipping the sharpening stone over the counter5. DOUBLE-SIDED WHITE STONE: Sharp pebble water stone consists of highly resistant silicon carbide double-sided grain 400/1000. Grit 400 is used to restore the edges to their original shape. Grit 1000 is used to sharpen and smooth the edges. Flattening Stone is used to even out and flatten the uneven surface caused by repeated use. Since it is a water stone - no expensive honing oil required!