Flexible knit upper hugs your foot for a perfect fit. Twin gore stretch inserts enhance the easy on/off design of this slip-on. Breathability: Knit design is breathable and lets air flow freely to help keep feet cool. The soft lightweight molded sole provides durability and shock absorption along with stability and flexibility. A contoured footbed with arch support is lined in soft quilted microfiber molds to your feet. EVA outsole provides lightweight shock absorption while still being flexible.