Gauges: 10-13-22-28. D"Addario J97 Bouzouki Strings are nickel-plated steel wound. 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. 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 string set that"s right for your bouzouki.