Prelude Bass Strings by D'Addario are crafted with a special stranded steel core designed to provide optimum playability for developing/beginning bassists. They have good bow response and a clear, warm tone that is even from string to string and blends well with the rest of the orchestra. These entry level strings have the hi-quality you expect from all the D'Addario strings. D'Addario challenges other school or student strings with their impressive Prelude line. Made in USA. Available in Fractional Sizes, too! R-U Looking to upgrade your strings? Check out Helicore Bass, also by D'Addario. Helicore comes in Arco, Pizzicato, Hybrid, and Solo Tuning Sets.