The D'Addario EJ15-3D Phosphor Bronze Extra Light Acoustic Guitar Strings gives you three sets in the one pack. D'Addario's lightest gauge of acoustic strings, EJ15s are ideal for beginners or any player that prefers a softer tone and easy bending. 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 EJ15-3D Phosphor Bronze Extra Light Acoustic Guitar 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.