Designed and gauged for the mandobass * Copper coated steel wound * Made in the U.S.A. for the highest quality and performance * String Gauges: Wound .049, .063, .097, .130 * D"Addario J79"s are designed for the larger bodied mandobass. The four copper strings are tuned to EADG and are perfect for bluegrass and classical styles of music. Copper Wound Mandobass strings are known for their bright acoustic tone and versatility across multiple genres and playing styles. D"Addario, the world"s largest manufacturer of musical instrument strings, is known as The Players Choice with a reputation for unsurpassed quality and consistency. D"Addario"s innovative, environmentally friendly packaging reduces waste and provides protection from corrosion. All D"Addario strings are manufactured in the U.S.A. using proprietary, digitally controlled, state-of-the-art machinery for unmatched performance, set after set.