Martin Strings are the acoustic string of choice for musicians around the world. Wound to exacting specifications, you can depend on these strings for tone, brightness and clarity on a daily basis.These 80/20 bronze strings deliver a superb bright sound.  This alloy is comprised of 80% copper and 20%
zinc. It is popular for acoustic strings and provides a very brilliant tone when
they are initially put on the guitar and mellow over
time.  High carbon steel with
tinplating is used for the core wire of wrapped strings and
the plain round treble strings.

Gauge

M140 - 12, 16, 25, 32, 42, 54. (Light)