Thomastik-Infeld Plectrum Extra Light Acoustic Guitar Strings are soft sounding and have low tension on the bottom end. The E and B plain strings are made of brass coated steel. The wound strings have a silk inlay combined with a highly flexible steel core. A, D, and G strings are polished bronze flatwound, while the low E is polished bronze roundwound.Gauges: .010 - .013 - .016 - .022 - .030 - .041.