Pitbull acoustic guitar strings GOLD series new version are manufactured with the combination of the most compatible raw materials. They are made of phosphor bronze windings and high carbon alloy American made hexagonal steel core, with stable tuning features. Gold series are the flagship of Pitbull Strings, loved by musicians all around the world. These strings are produced to the highest standards with all musical needs, playing comfort and sound quality in mind. Their shelf life is due to our super VCI packaging system. The Gold series are the choice of professionals.