FLYTEFOAM® Propel Technology ASICS energetic foam formulation that provides supreme bounce thanks to a unique elastomer compound. Rearfoot and Forefoot GEL® Technology Cushioning System Attenuates shock during impact and toe-off phases, and allows movement in multiple planes as the foot transitions through the gait cycle. Lightweight AHAR™ Outsole Acronym for ASICS High Abrasion Rubber. Lighter weight material placed in critical areas of the outsole for exceptional durability. Engineered Mesh Upper Multi-directional mesh material improves ventilation and Size 81/2