Synthetic-and-mesh Imported Rubber sole GEL Technology: Cushioning provides excellent shock absorption Engineered mesh upper: Improves airflow. Ortholite Sockliner: Moisture management (Ortholite is a registered trademark of O2 Partners LLC). Flex grooves in the outsole: Strategically located grooves in the outsole improves flexibility Synthetic stitching: Synthetic fiber stitching on the overlays improves support