JS-12 II is designed with a lightweight 6.6mm shaft, which is 8% lighter than the previous 6.8mm shaft and also reduces the wind resistance by 2.9%. The strength of the frame is also improved by 17.5% with the help from NANOFORTIFY TR+ material. The material property of PYROFIL greatly enhances the overall elasticity. What’s more, the FREECORE synthetic handle technology is integrated into the high-end Speed series racket for the very first time, making the hitting more stable and comfortable.