The 25th Anniversary Of This Legendary Runner Includes The Next Evolution Of Our Ultra-lightweight Flytefoam Cushioning: Flytefoam Propel And Flytefoam Lyte. These Two Cutting-edge Technologies Work Together To Deliver Energized Cushioning And Exceptional Comfort From Heel To Toe. Count On Gel-kayano 27 For A Premium And Reliable Ride That Stabilizes Your Foot And Fits To Perfection.