Only worn once, selling because need 1/2 size bigger. DESIGN: Mesh upper is engineered for structure, flex and ventilation Bootie construction and asymmetrical lacing system creates secure fit Clear rubber on the heel highlights the Max Air unit IN-SHOE COMFORT: TPU heel counter creates smooth transition to Max Air heel unit Large volume Max Air unit creates impact absorption and cushioning Dual-density foam tooling uses rigid and softer foam to create superior cushion Flex grooves help create smooth transitions