Phosphor bronze was introduced by D'Addario into string manufacturing in 1974 and has since become synonymous with a warm, bright, and balanced acoustic sound. D'Addario's phosphor bronze strings are precisely wound with corrosion-resistant phosphor bronze onto a carefully drawn, hexagonally shaped high-carbon steel core. The result is a durable, bright-sounding tone with excellent intonation. D'Addario offers a complete range of single strings for acoustic guitars to cover all your replacement or customization needs. This .035 gauge phosphor bronze string is favored for its warm, bright, and balanced acoustic sound. It is perfect as a replacement string or for creating custom sets. Made in the USA for the highest quality and performance.