The Whetstone King for the Kitchen knife.  
<br /> The set includes Four kinds of sharpener:  
<br /> 320# Blue Gem oil stone 
<br /> Boron carbide sharpening stone, is a harder oil stone, it for optical instrument, instrument, the precision of the original cast grinding has unique effect, suitable for half cutter grinding, special wear-resisting, oil stone itself is not easy to scratch 
<br />800# Black Gem oil stone 
<br /> Dark ruby oil stone, the structure is very exquisite precision, belongs to the oil stone of hard wear-resisting, high grinding rate, hard alloy products, original precision grinding can be cast, it's on the knife ways of performance is outstanding, has incomparable open front performance 
<br />3000# Ruby Gem oil stone 
<br /> Ruby abrasive is made of high temperature sintering, has the very high hardness and strength, the product is rose red, fine texture and closely, has almost not easily worn surface, high hardness, toughness is suitable for machining of hardened steel, alloy steel, high precision measuring tool and instrument parts finish requirement artifacts, ruby sharpening stone only need to add a few drops of water when grinding blade, grinding blade is very sharp, suitable for cutting tool edge and fine 
<br />6000# WhiteGem oil stone 
<br /> Natural white jade, white stone oilstone organize uniform and dense, fine granularity, high hardness, used to remove particles, the wear and tear is small, long life and other characteristics of general oil stone not meet, is one of the best polishing abrasive for various materials such as metals, mainly used in instrument industry, precision parts, miniature cutter, gem, measuring tool, cutting tool, instrument and meter, hard alloy, etc 
<br />Please note: 6000# is a natural stone, color may be some dark 
<br />The Whetsone will be used in this sharpening system