... have single type,AA group type,AAA group type. MaterialPiano wire, stainless steel, High Carbon Steel, Nickel Plated, Phosphor ... copper Bronze, Copper Bronze, Beryllium Copper.Wire Diameter0.1 mm ~ 10 mm and above.Free LengthThe overall ... /Single Style of Ends positive pole/negative poleSurface FinishNickel / Zinc / Gold / Silver / Tin / Chromium / Yellow Zinc / Oxide black or ...