.012 .016 .024w .032 .043 .054 - 24 carat gold plated - E1, H2 and G3 consist of a high quality, nickel-plated steel wire and are additionally coated with real gold. D4, A5 and E6 - the core of these strings is tinned hexagonal steel, wrapped with gold-plated core wire. OPTIMA GOLD STRINGS - Probably the finest string in the world. Developed and handcrafted in Germany, made from the best materials and designed for the highest sonic demands. This series reflects our 75-year tradition in string production. The result is a premium quality string that is second to none. All strings are coated with real 24 carat gold and are therefore completely insensitive to tarnishing or corrosion. Their durability is up to three times higher than normal strings and are suitable for those allergic to nickel. 100% Made in Germany.