Nike Kids' Grade School Free RN Flyknit Running Shoes-Grey/Green. The Nike® Free RN continues to deliver comfortable support and lightweight cushioning. New to the Free family, the RN now features an auxetic tri-star outsole pattern that expands with each step; this promotes flexibility and natural motion. The strong Flyknit upper acts as a support wall, cradling their foot during lateral and lineal movements. Trusted Flywire technology continues to deliver lockdown support.