14. What's K9 crystal? how to choose good K9 crystal material, does LASERFOX provide the crystal blank material?

K9 crystal is now the crystal material all we can see in the market, this kind crystal material actually is optical glass, choosing right K9 crystal material is very important because some K9 manufacturers use low cost chemical ingredient glass material to make K9 crystal material to reduce their production cost, but such material may cause engraving problem, LASERFOX has its own production factory to control the quality and guarantee such problem never happen with our crystal block.