Gauges 12-46.D'Addario's octave mandolin strings are designed for usewith octave mandolins of various scales. The unwound strings are madefrom plain steel and the wound strings are phosphor bronze. PhosphorBronze was introduced to string making by D'Addario in 1974 and hasbecome synonymous with warm, bright, and well-balanced acoustic tone.D'Addario Phosphor Bronze strings are precision wound withcorrosion-resistant phosphor bronze onto a carefully drawn, hexagonallyshaped, high carbon steel core. The result is long-lasting,bright-sounding tone with excellent intonation.