XT are longest lasting classical strings, combining centuries of D’Addario expertise with modern coating technology. The Dynacore bass strings in this XT set use a revolutionary multi-filament nylon core processing technique to deliver unparalleled intonation, responsive attack, and crystal-clear projection—and with addition of proprietary XT coating, a significantly extended lifespan. Coupled with precision Titanium trebles, supplying distinct balance and increased resonance, XT Dynacore is the most advanced classical string available. This Hard tension set provides rich tone and strong projection.