Martin MA140 Authentic Acoustic SP 80/20 Bronze 12-54

Martin MA140 Authentic Acoustic SP 80/20 Bronze 12-54 Light Acoustic Guitar Strings.
 
These strings are engineered with the performer in mind and they will always stand up to rigorous practice and performance schedules. We start with our highest tensile-strength core wire, then tin-plate it on all six strings for added corrosion resistance; because what you don’t see matters! When coupled with our highest quality wrap wire you get consistent true tone that you can count on song after song.
 
String Guage: 
E - .012
B - .016
G - .025
D - .032
A - .042
E - .054