Set of high quality strings for acoustic guitars. Pitbull has developed high quality strings using the finest American steel wire. Pitbull produced the Gold Series with the material sounding the best. With Pitbull's technology background, the Gold series has an excellent balance of tension and tone with maximum sustainability. PITBULL GOLD, phosphor bronze strings contain 5% copper alloy and up to 1% of phosphorus. In the alloy, a small amount of phosphorus helps to keep the vibration longer. The strings are specially designed for perfect balance and tension. Custom Light, Thickness: .011, .015, .022w, .032w, .042w, .052w