Keep your knives sharp with the Zwilling Kramer Sharpening Stone. Your knives will obtain a sharpness that is durable over time in a matter of minutes. Features Made from synthetic ceramic whetstone Efficiently sharpens the knives to the desired sharpness Long-lasting sharpness achieved with minimal work Sharpens all types of knives, excluding ceramic Available in 5 grains for different requirements -400 Grit changes the angle of the edge or used when edge needs to be repaired. For very dull blades- 1000 Grit used for fine sharpening- 3000 Grit for fine finishing / basic polishing- 5000 Grit for extra fine finishing / fine polishing- 10000 Grit for the finest finishing with mirror polish Made in Japan