Khao Men Natural Whetstone - Fine: 3000 Grit + (9X3X3" - 6.5 PDS AVG) Extra Large Cuts for Large Knives - Lifetime or More of Use All Natural Whetstone - Mineral Formation from Oxygen Deprived Bog Extremely Rare Stone from Quarry in Southern Thailand Grit Determined through Scratch Pattern Comparison with 2000 Grit Diamond Plate Use with water only, No Oil, Not Dry, Water can be mixed with soap.