Design: A pull-tab at the heel provides easy on and off In-Shoe Comfort: Flywire technology loops through the laces on the side for midfoot containment The upper uses a breathable knit material throughout for a soft, stretchy feel. It gives your foot room to stretch as you run A new foam is lighter, softer and more responsive than previous versions so you can keep moving in comfort Durability & Traction: Laser-cut flex grooves offer more flexibility, with rubber at the forefoot and heel for durability Additional Details: Contains at least 20% recycled content