Genesis Spin X 17 (12m)-is the best string for advanced players with excellent comfort, power, spin, and control, Spin X is the ultimate winner. Spin X is made with the highest grade co-polymers. Through the patented SOHT method and is heated made with 8 external edges.Players will appreciate the long lasting performance and the excellent tension maintenance afforded by Spin X. For some added pop and spin potential, we recommend going with the 17 gauge.