Nail fitness fire in these women's Flex 2017 RN trainers from Nike. Built for next level seshes, Flywire tech locks the foot down for adaptive, responsive performance. Sat on a dual-density midsole/outsole that stays light, the rounded heel enhances the range of motion, while the tri-star outsole pattern shows off some serious flex when you hit the ground running.. Material: Textile Upper/Synthetic Sole