Dynafit Ultra 100 Trail Running Shoe Provides Maximum Cushioning and No Chock which allows our feet to feel comfortable and maintain the right pace. Heel Preloader technology and rocker platform work together to ensure fast and powerful transitions minimizing heel slip and pushing us forward while a generous set of lightweight foam pads softens every blow and charges every break. This pair is designed for a fuller fit. withstands swelling during long runs and seamless tongue construction minimizes pressure points and hides lace ends ensuring a secure fit.