D'Addario Helicore Orchestra Bass Strings*Basic Trial Sets limited to 2 per customer* Helicore Orchestral bass strings are multi stranded steel core strings that produce a warm tone quality with excellent bow response. The groundbreaking core design produces strings that are very easy to play. Damping is optimized for arco use, but they also work well for pizzicato applications where a very warm, less sustaining sound is desired. D'Addario