75% Synthetic, 25% Mesh Rubber sole N-ergy is a resilient engineered elastomer designed to provide shock absorption and responsiveness for the optimal ride ACTEVA is 12% lighter than standard midsole foam with DuPont Engage for exceptional durability Internal shank SURE LACE is a computer knit lace/chord designed with a reciprocating wave pattern that will not untie under high performance or inclement conditions Ndurance is a rubber compound for maximum durability used in high wear areas