The EJ65TLG Low-G Ukulele sets are designed for usage on tenor ukuleles. The 4th string is a silver-plated copper wound on nylon and complimented by 1st, 2nd and 3rd Pro-Arté Custom Extruded clear nylon strings. Each Custom Extruded Nylon sets are 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.