The controlled-angle sharpening system was designed by Arthur Lansky Levine in 1979. A first of its kind, the knife sharpening system was a hit with consumers, and remains our most popular item. The Lansky controlled-angle knife sharpening system is an easy-to-use sharpening solution that helps you get a razor sharp edge every time. It comes in seven kit varieties, with three to five sharpening hones per kit.