If you've never sharpened knives and want to actually keep your kitchen knives as sharp, if not sharper, than when they were new, buy this sharpening block. This is a guide that attaches to the back of the knife to ensure the correct angle. I used them, it was the first time I managed to sharpen a knife with such a stone. This is a wet stone, soak it in a water bath for at least 10 minutes before use. I'm going to buy a finer grit and see how sharp I can get my knives sharp, I'm so glad I can finally sharpen my own knives instead of looking for a machine. the shop that makes them. My first job as a teenager was in a professional kitchen and we all sent our Trident knives together to be sharpened. I was so proud of my fine chef's knife. Of course I engraved my initials on it so I get the same one every time. When I stopped working in that kitchen, I didn't have access to that service. Places that do this only charge a few dollars for a knife, but there's only a step or two that will do it. They've been in and out of business for decades. Finding them and giving the knives to sharpen is PIA. NO LONGER! Now I can finally do it myself. Cutting tomatoes is easy. i love this block