Ernie Ball Papa Het Signature Set Electric guitar strings 11-50Exclusive Gauge Combo The custom gauge 11 50 set was co developed with James Hetfield and designed to address his precise performance needs for tension and feel. Master Core Technology Features a heavier core to wrap ratio for a thicker sound and superior pitch stability under aggressive playing. Enhanced Durability The plain strings consist of Paradigm core wire with brass RPS reinforcement at the ball end for added strength and tuning stability.