The latest Asics GEL-Kayano 23 will continue to be a favorite for runners who've loved the cushioning and stability from this model over the years. The most significant change is an improved fit on the heel as well as for the entire foot. Runners will experience an update of lightweight and cushioned responsiveness from the added FlyteFoam™ technology. Moderate to severe overpronators alike will benefit the most from this highly supportive running shoe.Upper: FluidFit® combines multi-directional stretch mesh with stretch reinforcements that adapt to the athlete's foot, creating a truly customized glove-like fit. Heel Clutching System™ exoskeletal heel counter provides improved support and creates improved heel fitting environment. Padded tongue and heel collar enhance comfort. Lace-up front offers an adjustable fit.Midsole: FluidRide™ provides the ultimate combination of bounce back and cushioning properties with reduced weight and exceptional durability. Dynamic DuoMax® Support System enhances stability and support, with reduced weight and increased platform comfort. Impact Guidance System (I.G.S®) employs linked componentry to enhance the foot's natural gait from heel strike to toe-off. Rearfoot and Forefoot GEL® Cushioning Systems attenuate shock during impact and toe-off phases, and allows movement on multiple planes as the foot transitions through the gait cycle. ComforDry™ X-40 Sockliner provides cushioning performance and anti-microbial properties for a cooler, drier, healthier environment. Removable insole. Outsole: Guidance Line® vertical flex groove decouples the tooling along the line of progression for enhanced gait efficiency. AHAR® (ASICS High Abrasion Rubber) placed in critical areas of the outsole offers exceptional durability and traction.