ASICS GEL-Cumulus 21 SP Men's Running Shoes Sheet Rock/Mako Blue : The new Asics GEL-Cumulus 21 Sp is back with impressive updates for the neutral runners who love reliable cushioning and comfort. A new contoured sockliner better matches the natural shape of the foot for a better fit. Bottom layer of the midsole features the FLYTEFOAM Lyte technology for better cushioning and comfort. Also, the grooves in the sole just under the heel have been adjusted for a softer landing. The collar has been modified with more foam and less adhesive for a more comfortable ankle wrap. The GEL-CUMULUS features the same last use in the GEL-KAYANO 25 and 26, with more height in the toe box and across the ball of the foot. Technology Upper: Features a multi-directional mesh that is knit in a way that provides more support in some areas and more space between the yarn in other areas to reduce the weight and enhance breathability. An internal heel counter provides support and stability. It is positioned between the internal and external fabric in the rearfoot to reduce the chance of irritation. Midsole: FluidRide combines cushioning and lightweight responsiveness. Impact Guidance System (I.G.S.) employs linked componentry to enhance the foot's natural gait from heel-strike to toe-off. GEL Cushioning Systems attenuate shock during impact and toe-off phases and allow movement in multiple planes as the foot transitions through the gait cycle. FlyteFoam Midsole technology is lightweight and provides long-lasting, responsive cushioning. Outsole: Guidance Trusstic System provides a lighter and stable outsole. AHAR ASICS High Abrasion Rubber placed in critical areas provides exceptional durability.