These running shoes are designed with ultra-runners in mind. have both the shock absorption necessary to cover the distance as well as grip and stability necessary for rough terrain. In addition to a more powerful midsole which softens impacts and provides comfort during all-day racing , this shoe has several stabilizing features for the trail including an internal stone plate and polyurethane inserts in the midsole. At the same time, the high-grip rubber on the outsole provides stability on steep mountain trails.