Check the listing for details. D'Addario Zyex Series Double Bass Low C (Extended E) String 3/4 Size Medium. Condition: New. Listed at 86.94 USD. Zyex synthetic core double bass 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.All D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry.