Martin Guitars Authentic Acoustic SP 92/8 Phosphor Bronze Strings Promo Pack - 13-56 Medium

Authentic Acoustic Superior Performance Strings
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.
This Promo Pack includes 3 sets of 13-56 Medium strings.

Specifications
Gauge: Medium
E: .013
B: .017
G: .026
D: .035
A: .045
E: .056
Tension: 190.9