Lightweight, Breathable Synthetic/Mesh Upper - Provides exceptional air flow to keep your feet cool, along with support. Synthetic Overlays - Provide structure and support. Padded Tongue - For extra comfort and a snug fit. Removable Sockliner - For increased comfort. Can be removed to accommodate an orthotic. Rearfoot GEL Cushioning - Provides heel cushioning in all directions, as well as shock absorption.