The Nike Flex 2016 RN Running Shoe features a one-piece engineered mesh upper and a tri-star outsole pattern for enhanced flexibility that moves with your stride. Engineered mesh upper for flexibility and breathability. Phylon midsole with two levels of cushioning for a smooth ride. Tri-star outsole pattern enhances flexibility. Flywire technology provides a locked-down fit. Rubber pods at heel and toe for traction and durability.