D'Addario DZ310A Zyex Violin String Set, 4/4 Scale, Medium Tension Zyex synthetic core strings produce a balanced, 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. -Aluminum Wound D