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.