12-16-24W-32-44-54 Lenth 43 inches. Phosphor Bronze wound strings were introduced in the early Seventies and have become the most popular acoustic string. Phosphor bronze wire is made from approximately 92% copper, 7% zinc and 1% phosphorous. Phosphor Bronze provides nice highs and lows with pleasant subtle overtones. Phosphorous is used to help reduce tarnish and corrosion. Our in house coating blend was designed to preserve the life of the strings and deter corrosion. The coating was composed in a way to preserve the original sound and feel of the strings.