Thomastik-Infeld Strings for classic guitar CLASSIC GUITAR CRK - Set high tension (CRK125HT)CLASSIC GUITAR CRK The legendary Adamas Phosphor Bronze new Thomastik Infeld CRK CLASSIC Carbon nylon hybrid material guitar strings that captivate with the brilliance and power of carbon strings and have the warm, rich sound usually only found on nylon strings. The new hybrid material from Thomastik is inspiring with its immediate response and translates every impulse of your fingers. Treble strings: Carbon nylon hybrid material, clear, see through