D'Addario's most popular acoustic set, EJ16 Phosphor Bronze strings deliver the ideal balance of volume, projection and comfortable playability. Phosphor Bronze was introduced to string making by D'Addario in 1974, and has become synonymous with warm, bright and well-balanced acoustic tone. D'Addario Phosphor Bronze strings are precision wound with corrosion-resistant phosphor bronze onto a carefully drawn, hexagonally shaped, high carbon steel core. The result is long-lasting, bright-sounding tone with excellent intonation.