size 6.5fits size 5.5-6 size 9.5 fits size 8.5-9 No shoe box With two layers of Clouds, the Cloudultra adds another level of cushioning to your long runs and ultra marathons. Wrap-fit construction fits like a sock, with two layers of sandwiched mesh for impressive breathability and durability, and a FlipRelease™ tool on the forefoot lacing to release pressure when your feet start to swell. Upper uses breathable knit mesh and asymmetric overlays to wrap your foot Sock-fit construction is comfortable and secure FlipRelease™ mechanism releases lace tension at the push of a button Helion™ superfoam delivers a smooth ride with soft landings and energy-filled toe offs Integrated speedboard imparts a natural flex and rocker, encouraging a smooth roll off Double layered CloudTec® pods compress under impact to absorb shock and provide responsive energy return Missiongrip™ rubber outsole for grip and durability on and off road