D'Addario Zyex Upright Bass String Set, 3/4 Scale, Medium Tension 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. Settling in on the instrument within a matter of hours, Zyex bass strings provide rich, gut-like, complex tone, combined with power and clarity for both pizzicato and bowing. Zyex bass strings were developed primarily to offer outstanding pizzicato attacks and sustain, as well as superb bowing response. Get the sound and feel of gut strings with more evenness, projection and stability than real gut.