Medium 12-string set for acoustic guitar from Earthwood 80/20 Bronze Acoustic series that provides a crisp, brighter sound with lots of clarity and pleasing overtones. Strings are made from 80% copper-20% zinc wire wrapped around hex-shaped tin-plated steel core wire. They are precisely manufactured to the highest standards and most exacting specifications to ensure consistency, long life and optimum performance. Gauges: .011/.011, .015/.015, .024w/.010, .030/.014, .042/.022w, .052/.028.