These Ernie Ball Earthwood 80/20 Bronze Alloy Banjo Bluegrass Strings are manufactured in the USA to the highest standards. With a gauge of 9-20, these Earthwood strings provide bright and balanced tones with crisp and pleasing highs. As the most popular acoustic guitar strings, they are ideal for players who enjoy a bright, sparkling sound with excellent intonation. These 80/20 strings are precision wound from 80 copper and 20 zinc and they come as a 5 string set. The Banjo Bluegrass strings provide bright and traditional banjo sounds. The Earthwood gauge 9-20 are manufactured to ensure optimum performance and long life.