YONEX new Synchro-Fit Insole construction allows a closer fit between shoe and foot, keeping power loss to an absolute minimum to achieve smoother movement and quicker footwork.Fig1. Compared to conventional footwear, the mid to heel area on the insole is lifted to provide a closer-fit between shoe and foot.Fig2. By holding the heel more firmly against the insole, the gap between shoe and foot is reduced, improving comfort and ensuring the foot does not slip forwards inside the shoe.