Never have I used a knife sharpener until I tried this Ninja knife sharpener, you can use it on your own knives and it sharpens time so good till I had cut a small watermelon with no problem. It’s slam enough to fit right on my counter top, very easy to clean and it will sharpen any knife you have in your kitchen as long as it’s the right size. My son tried to take it from me because it’s a great tool and my family will be purchasing one.