Double-Sided Grinders: The grindstone set features a high quality double-sided grindstone (400/1000 3000/8000), a bamboo base for attaching the grindstone and an angle guide for grinders. The safety cutting machine angle guides allow you to maintain the correct angle and apply constant pressure in a safe manner and sharpen the blade quickly. Easy to clean: The millstone is made of Kornam, does not require expensive oil and can only be done with water. Non-slip bamboo base: Non-slip bamboo pads ensure everything is secure, so you don't have to worry about the whetstone slipping off the work surface. Universal: professional quality whetstone is very practical and durable.This sharpening stone can be used for kitchen knives, garden tools, wooden tools (not for toothed blades and ceramic knives).