Martin Phosphor Bronze Acoustic Guitar Strings are made from 92/8 composition alloy to give brilliance, clarity, and longevity of sound. The Phosphor Bronze winding is ideally suited for making strings that have deep, rich basses and clear, bright trebles.
Gauges:
M530 Extra Light 10-14-23-30-39-47
M535 Custom Light 11 15 23w 32w 42w 52w
M540 Light 12-16-25-32-42-54
M545 Light/Medium 12.5 16.5 25.5 33.5 43.5 55
M550 Medium 13-17-26-35-45-56