D'Addario EJ65B Pro-Art Custom Extruded Nylon Ukulele Strings BaritoneEJ65B is a string set for baritone ukulele, utilizing Pro-Art Nylon trebles for the E and B strings, paired with wound Nylon Core strings for the G and D. Pro-Art Custom Extruded Nylon sets the standard in terms of ukulele tone, intonation, and dynamic response.D'Addario EJ65B strings are designed specifically for baritone ukuleles. The 3rd and 4th string are a silver-plated copper wound on nylon and complimented by a 1st and 2nd Pro-Art Custom Extruded clear nylon strings.