Zyex synthetic core strings produce an extremely warm, rich sound. Zyex is a new generation of synthetic material, creating strings that are extremely stable under drastic climatic conditions. Zyex strings settle in on the instrument very fast, within a matter of hours. Zyex has a warmer sound than most other synthetic core strings, making them excellent for use on brighter sounding instruments. Medium scale viola strings are specifically gauged to fit medium-scale viola (body length 15-15 3/4 inches) with a playing length of 14 1/8 inches (360mm).