Diamonds outperform all other types of sharpening abrasives. These quality sharpeners are laminated onto a high carbon steel plate. Utilizes exclusive knife clamp/angle guide that is extrememly strong and allows for angles of 29, 25, 22, 19, 15 and 11 degrees. Contains coarse(200-grit), medium(400-grit) and fine(600-grit) hones impregnated with monocrystalline diamond, honing oil and custom case. Made in USA.