Thomastik-Infeld 137 Dominant Nylon Core Viola String, Medium Gauge, 4/4 Scale, D Made with a highly flexible, multi-strand synthetic core Provide the tonal warmth and feel of a gut string while being impervious to changes in humidity The sound is soft, clear with a stable intonation and they are rich in overtones Its radiance and ability to project sound without being metallic comes to the fore both in Arco and pizzicato passage Effortless response to intricate fingering and its tuning stability even under extreme atmospheric conditions