The Martin SP Studio/Performance Series strings are ideal live, in the
studio, or wherever maximum string life is desired. The creation of
these new high performance strings is a result of research done in
cooperation with specialty steel producers. Due to the development of
an industry leading ultra-high quality steel core, Martin SP strings
resist breakage better than average strings. In addition, both the core
wires and the plain strings are plated with a smooth, acoustic bronze
finish. Though this golden bronze finish does enhance the beauty of
your guitar, its purpose is much more functional - to prolong
brightness, string life, and superior tonal quality to meet the high
expectations of demanding musicians.

Gauge

MSP3000 - 10, 14, 23w 30, 39, 47. (Extra Light)