D'Addario DZ310 1/2M Zyex Violin Strings, Medium Tension, 1/2 Size Set Overview Features Zyex violin strings are designed for the discerning musician. Made from Zyex synthetic core material for a powerful sound and excellent bow response. The Zyex core provides pitch stability, fast break-in time, and a gut-like, resonant sound. These are new and unopened, but due to being stored at home, there may be some minor scuffs on the packaging. Please understand this before purchasing. Thank you.