Such a simple design and so effective. Easy to open and easy to lock. Please understand, carbon steel will develop a patina. This is the beauty of carbon steel. Compare to stainless steel, I find carbon steel is easier to sharpen and to maintain an edge. . These will last forever with a little care. I always wash by hand and oil after use. For years, I have used a good vegetable oil. I am going to try the Tsubaki Camellia Oil. I love both the #10 and #12 for food preparation. The #12 is stainless steel so it is reserved for acidic foods. I love the #10 for hiking and picnics.
You can literally hone this blade until it's as sharp as a surgical scalpel... I have never owned a knife that you can get as sharp as this one.. and it stays Sharp as long as you take care of it. It's super lightweight, you can't even tell you're carrying it around, but it's Stout enough that you can put it through some pretty good use and nothing's going to loosen on it, and the ring lock system make sure the blade stays locked open. You're not going to find a better knife for this price.