This set has been specifically designed for resophonic guitars, using the most popular tunings and gauges. As a part of La Bella's Phosphor Bronze Series, these sets are made with our exclusively formulated bronze and tin alloy, producing a brighter tone and longer string life than any other phosphor bronze set on the market. Since its introduction in the 1970s, the Phosphor Bronze Series has become our most popular acoustic set for all genres of music.