The Lansky Controlled-Angle Sharpening System is designed to give your blade a professional, razor sharp edge every time. The ultimate in knife sharpening systems technology. It is safe, easy and convenient to use. Diamonds remove steel much faster than their alumina oxide counterparts. For knife enthusiasts, you might want to invest in one Extra Fine or Supper Sapphire ceramic hone to polish your blade to a mirror finish and a serrated hone to truly complete your ultimate kit.