Avia Women's CC Release Tech A5781W, 100% Synthetic Rubber sole Breathable Mesh Upper - Excellent ventilation for your feet giving you a breathable workout Lightweight Synthetic Overlays - Air mesh lining with synthetic overlays wicks away moisture and enhances midfoot support Removable Cushioned EVA Insole - Washable, Odoerfree, Breathable, Antibacterial and Shock Absourbing Carbon Rubber Heel - A high-abrasion carbon rubber compound which is placed in high-wear areas to increase outsole durability. Compression Cushioning Technology (CC-Tech) - Provides heel stability and cushioning throughout your foot-strike.