10 SETS - MARTIN MA150 ACOUSTIC GUITAR STRINGS MEDIUM (13-56) 80/20 BRONZE

Extra Lights - Most likely a little thinner than what your guitar came with new. A bit easier to play/bend, but will also have a little lighter tone.
Lights - MOST NEW GUITARS COME WITH LIGHTS. By far the most popular gauge of string. Light enough for easy playing, but thick enough for a good full tone. Our recommendation if you're unsure.
Mediums - In the acoustic world, this is the heaviest standard gauge of string. Firmer to play, but will also give you a nice full tone. Many heavy strummers prefer mediums.

10 SETS - MARTIN MA150 ACOUSTIC GUITAR STRINGS MEDIUM (13-56) 80/20 BRONZE

Martin MA150 Medium Acoustic Guitar Strings have an 80/20 composition for brilliance, clarity, and longevity of sound. The Bronze winding alloy makes guitar strings have deep, rich basses and clear, bright trebles. The Martin MA150 acoustic string pack comes with Martin's high-quality guitar strings for daily use. Core and wrap wires meet strict requirements that make the grade because Martin guitar strings are wound to precise specifications.

Gauges: 13-17-26-35-45-56

Features:
Bronze alloy for brilliance and long life
Studio-quality performance