We are a manufacturer of pull-through knife sharpeners that actually work on all types of knives, even serrated. Each set of steels is similar to butcher steel, only crossed at a 44-degree angle, taking all the guesswork out of sharpening a knife. Sharpeners come in four types of steels to restore, sharpen, hone and polish your blade without ruining your knives. We offer a lifetime warranty, and our products are made in the USA. (less)