Medium Gauge Variety Includes:
Martin MA150T 13-56 Medium 80/20 Bronze Treated Acoustic Guitar Strings - 41Y18MA150T
Martin MA150S Authentic Acoustic Marquis Silked 80/20 Medium 13-56 Acoustic Guitar Strings - MA150S
Martin MA550 Medium 13-56 Phosphor Bronze Acoustic Guitar Strings - MA550
Martin MA550T Treated, 13-56 Medium, 92/8 Bronze Acoustic Guitar Strings - MA550T
Martin MEC13 Eric Clapton's Choice Medium Phosphor Bronze Acoustic Guitar Strings - MEC13
