Color ClassificationA: Silver wire blue shell platinum plated silver + silver plated wireB: Black wire black shell gold-plated silver + silver-plated wireC: black wire red shell black silver + silver plated wireD: Silver wire, blue shell platinum plated silver + pure single crystal silver wireE: black wire black shell gold-plated silver + pure single crystal silver wireF: black wire red shell black silver + pure single crystal silver wireReincarnation Absolutely Sound Version Outer shiny 925 silver shell (platinum plating or 24K gold process) Reinforced cavity to reduce resonanceMusic lovers are welcome to join the official group of Kai & Ksearphone 16758178