Zyex synthetic core strings produce an extremely warm, rich sound. Zyex strings are made from a new generation of synthetic material, creating strings that are incredibly stable under drastic climatic conditions. Within a matter of hours, Zyex settles in on the instrument with a sound that is warmer than most other synthetic core strings. Zyex is also an excellent choice for use on bright sounding instruments. Scaled to fit 4/4 size violin with a playing length of 13 inches (328mm), these strings will allow for greater projection and volume potential. The D string included with the DZ310A set is aluminum wound, and the D string included with the DZ310S set is silver wound. Packaging in uniquely-designed sealed pouches provides unparalleled protection from the elements that cause corrosion. 4/4 scale violin with a playing length of 13 inches (328mm) Zyex synthetic core produces a rich, warm tone Short break-in time and excellent bow response provides superb playability and a broad tonal palette All D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry