This sharpener should be in every knife owners arsenal. You can sharpen knife blades on it sure, but its best use is for serrations and fish hooks. I use the v sides to sharpen the serrated edges on my knifes and it works quite well. Look up some video reviews of it on Youtube, it works great! On top of that it has a small groove cut into one of the stone sides, this is for sharpening your fishing hooks and it works really really well. A professional angler once told me that most mistakes newbies make is using dull hooks that wont set all the way through when pulled. You want that hook to pierce thru the lip or cheek of that fish and dull hooks will just slide out of the fishes mouth without piercing. That alone is enough to buy this tool and toss it in your tackle box. I use my serrations on my knife all the time. This little baby gets the nicks and dings out and sharpens them back up like new again.