Manmade,Mesh Imported Rubber sole SpevaFoam Midsole Material – Improves bounce back characteristics and decreases midsole breakdown. Guidance Line?Midsole Technology – Vertical flex groove decouples the tooling along the line of progression for enhanced gait efficiency. AHAR Outsole – Acronym for ASICS High Abrasion Rubber. Placed in critical areas of the outsole for exceptional durability. Rearfoot GEL technology cushioning system – Attenuates shock during impact phase and allows for a smooth transition to midstance. DuraSponge Outsole – A blown AHAR rubber compound for enhanced cushioning and durability in the forefoot.