Gauges: 15-25-35-52. For over 200 years, D"Addario has led the way in string technology. Innovations such as computer controlled windings, laser micrometer inspection, and closed-loop tension control systems result in unrivaled quality and consistency. Set of 8 phosphor bronze. D"Addario is the world"s largest manufacturer of strings for musical instruments. Many top guitarists won"t play any other brand. Regardless of your playing style, D"Addario has a set of strings that"s right for your mandola.