Seamless upper with FluidFit stretch mesh for a comfortable fit that moves with you. Heel Clutching System locks the foot in place for a secure fit. Rearfoot and forefoot GEL® Cushioning Systems cushion and absorb shock. Impact Guidance System uses linked componentry to create a natural running stride. Propulsion Trusstic System mimics the foot's connective tissue, creating tension to propel you forward. Rubber outsole for durable traction. Wt. 10.1 oz.