ASICS Men's GEL-Noosa Tri 7 Running Shoe 100% Synthetic and mesh Rubber sole Impact Guidance System (I.G.S.) ASICS design philosophy that employs linked componentry to enhance the foot's natural gait from heel strike to toe-off. Guidance Line Vertical flex groove decouples the tooling along the line of progression for enhanced gait efficiency. Propulsion Trusstic Mimics connective tissue in the foot by creating tension as foot enters propulsion stage. Dual Density Solyte Lasting Employs different densities of Solyte lasting material in heel and forefoot for improved comfort.