Rearfoot and Forefoot GEL® Technology Cushioning SystemAttenuates shock during impact and toe-off phases, and allows movement in multiple planes as the foot transitions through the gait cycle.PGuard™ Toe ProtectorEnhanced toe durability.Flexion Fit® UpperProprietary upper which provides form fitting comfort without sacrificing support.P.H.F™ (Personal Heel Fit) Collar Lining2 layers of memory foam line the collar and mold to the athlete’s heel, creating a personalized fit.Solyte® Midsole MaterialA lighter weight midsole compound than ASICS standard EVA and SpEVA® midsoles. Also features enhanced cushioning and durability.Lateral propulsion trussticAHAR® OutsoleAcronym for ASICS High Abrasion Rubber. Placed in critical areas of the outsole for exceptional durability.Propulsion Trusstic® TechnologyMimics connective tissue in the foot by creating tension as foot enters propulsion stage.