The Gibson SAG-BRS10 80/20 Masterbuilt Premium Acoustic Guitar Strings are a set of 6-string acoustic guitar strings, made from bronze, that are unwound, with a super ultra light gauge from .010-.047. These strings are especially designed for use with Gibson Montana flat top guitars, but will provide excellent response on any acoustic guitar. Gibson have been producing strings since 1907 so the expertise and experience of the company guarantees satisfaction.