Ernie Ball Skinny Top Heavy Bottom Slinky Strings are the perfect hybrid set for those who like thick bottom strings without sacrificing the ability to solo on smaller strings. These strings are precision manufactured to the highest standards and most exacting specifications to ensure consistency, optimum performance, and long life. The wound strings are made from nickel plated steel wire wrapped around a hex shaped steel core wire.  The plain strings are made of specially tempered tin plated high carbon steel; producing a well balanced tone for your guitar. Gauges .010 .013 .017 .030 .042 .052. Part number 2215.