80/20 bronze medium gauge acoustic guitar strings, offering reliable sound quality. - Brand: Martin - Model: M150 - String Type: 80/20 Bronze - Size: Medium - String Gauges: E-1: .013, A-2: .017, D-3: .026, G-4: .035, B-5: .045, E-6: .056 New, unused, but has been stored at home for a long time. The box is partially open. For those who understand.