Martin® Authentic Acoustic® Superior Performance SP® strings feature higher tensile strength and tin-plated core wire on all six strings that enable a fuller and more balanced tone, quicker response and increased tuning stability. Martin's impeccable standards for acoustic guitar tone are embedded in their string design and precision manufacturing process. That’s why they make their own.

String Gauges:    .010    .014    .023    .030    .039    .047