to create abrasive slurry for effective sharpening with less pressure than an oilstone requires Combination stone has 4000 grit on one face for maintaining and refining, and 8000 grit on the opposite face for polishing steel cutting edges Cleans up easily with Water as lubricant instead of oil Blue plastic hinged box with no-slip can be used as holder for the stone during sharpening The Japanese-style 4000/8000-grit combination creates an abrasive slurry for effective sharpening, with 4000 grit on one face for maintaining and refining a , and 8000 grit on the opposite face for polishing cutting edges; This 18*6*3cm (H x W x D) stone, suitable for bench use, cleans up easily with Water, and comes encased in a blue plastic hinged box. The removable box lid, with no-slip , acts as a sharpening station to hold the in place during bench use. Sharpening stones, or whetstones, are abrasive surfaces used to sharpen and hone the edges of steel cutting implements such as chisels, knives, scissors, hand scrapers, and plane blades. Sharpening is the process of creating or re-establishing a by grinding away portions of the metal to adjust the angle of the edge and reform the shape. Package Contents: 1 x Sharpening stone Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.