Medium 6 string set for acoustic guitar from SP Flexible Core series that is the choice of Tommy Emmanuel, night after night. These marry Martin’s thinnest core wire to the standard tensions and provide total flexibility and total control. They feel soft to the touch which makes them ideal for beginners. The strings are made with the highest quality bronzed steel core wire and 92/8 phosphor bronze wrap wire. Gauges: .013, .017, .026, .035, .045, .056.