Review on Bora 501057 - Premium Combination Sharpening Aluminum for Ultimate Tool Precision by George Johnson

So many reviews from people who are clearly more experienced at complaining until 'someone fixes it for them' than trying to fix problems. Any sharpening stone requires maintenance to keep it sharp, as sharpening the blade wears the stone unevenly. This is achieved with a "smoothing stone" that can be used to remove rough edges left over from the shaping process. They only cost a few dollars. It's a cheap stone. It is used for practicing and maintaining tools in workshops (chisels, etc.). If you ruined your expensive Japanese knife with it, it's your own fault for not buying an expensive Japanese sharpening stone. Seller is under no obligation to include a complete beginner's knife sharpening guide in the product description. Next time, do a little research before making a purchase that requires knowledge and skill to use properly.