D'Addario EJ88C sets are designed for use with all concert ukuleles. Each string within this set is made from our exclusive Nyltech material and optimized for standard GCEA tuning. Optimized for Concert Ukuleles tuned to standard GCEA tuning Exclusive Nyltech material for traditional Ukulele tone Preferred for warm, gut-like overtones String Gauges: Nyltech .024, .031, .037, .026 Made in the U.S.A. for the highest quality and performance