Ernie Ball RPS Power Slinky Nickel Wound 11-48 strings. A patented winding of bronze wire is tightly wrapped around the lock twist of the ball end of plain strings. String slippage and breakage are minimized at the ball end where these most often occur. Plain strings in RPS sets last longer and stay in tune better than conventional plain strings. Wound strings are the same used in SLINKY NICKEL WOUND. The strings gauge .011 .014 .018p .028 .038 .048