QUALITY MATERIAL: Specially formulated high-grade grade corundum is constructed for professional results STANDARD COMBINATION SHARPENING STONES: This starter stone has coarser grit levels to repair damaged edges or blunt knives; Use with the Mercer Finishing stone M15952 to eliminate burs on the knife edge KNIFE RESTORATION: Keep cutlery performing at peak levels with this sharpening stone; Includes a different grit level on each side (400/1000) for more precise sharpening SAFE SHARPENING: Rubberized base holder gives you a secure surface for sharpening; Helps prevent damage to work surface, and safer storage MERCER CULINARY: Mercer continues to introduce innovative, quality products allowing foodservice operations to run effectively and efficiently; perfect for professional use or the home cooking enthusiast