Lace-free upper for easy on/off. Cool mesh tongue offers ventilation. Lightweight inflatable chambers manufactured from tough urethane film, laminated with expandable fabric, strategically positioned to fit and support the foot. Graphite arch bridge provides added support and stability, graphite material is as strong and durable as steel, yet 45% less than the traditionally used foam and heavy rubber. Bi-pod outsole for traction and stability. High abrasion rubber plug gives durability and long wear.