This 10 string pedal steel set is optimal for E9 tuning. These are precision manufactured to the highest standards and most exacting specifications to ensure consistency, optimum performance, and long life. All wound strings are made from nickel plated steel wire wrapped around a hex shaped steel core wire. Meanwhile, the plain strings are made of specially tempered tin plated, high carbon steel producing a well balanced tone for your guitar Gauges .013, .015, .010, .014, .018p, .022w, .026, .030, .034, .038