The Nike Air Sock Racer Ultra Flyknit is a brand new lightweight reworking of the 80's runner the Air Sock Racer. It features a one-piece Flyknit upper and a dual density foam midsole with an enclosed Zoom Air unit. The outsole has ridges 'hot-knifed' into it to improve movement and flexibility. The synthetic leather straps guarantee a perfect fit. A slightly weird but wonderful new style from Nike that is perfect for warmer weather.