Detail 01
Medium gauge
Identifies this MM13 set within the Martin Retro acoustic-string range.

Independent shopping perspective
Martin MM13 Retro Medium strings are an acoustic-guitar set using a SOLID nickel/copper alloy blend. The design reduces pick attack so the guitar’s wood character can remain more audible, while the stated response combines mellow body with crisp detail. Naturally corrosion-resistant wrap wire supports the set’s consistent-tone focus. This is the medium-gauge MM13 version of Martin’s Retro acoustic strings, priced at $9.99.

Strong match
What matters in use
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 01
Identifies this MM13 set within the Martin Retro acoustic-string range.
Detail 02
The alloy reduces pick attack so the guitar’s wood character is less overshadowed.
Detail 03
The wrap wire is naturally resistant to corrosion.
Final check
Product questions
Straight answers to the questions shoppers most often ask about this product.
They are acoustic guitar strings.
The stated character is mellow yet crisp, with reduced pick attack.