The EJ65C is an all-nylon string set designed for use with concert ukuleles. Each string is manufactured on D'Addario's own advanced monofilament extrusion line built exclusively for the production of musical instrument strings. Each set features our exclusive laser sorted Pro-Arté clear nylon trebles for unsurpassed intonation with a warm, projecting acoustic tone. This set is optimized for usage with standard GCEA tuning.