All wound strings are treated with groundbreaking nanotechnology that repels unwanted moisture and oils that negatively impact your tone. In addition to treating the wound strings, each plain string features a patented reinforcement winding of titanium wire. Titanium's inherent strength prevents string breakage, string slippage, and is proven to keep your guitar strings in tune better than conventional plain strings. Ernie Ball Slinky Coated guitar strings maintain the feel and sound of uncoated sets, combining the added protection with the vibrant tone Ernie Ball customers have relied on for over 50 years.