ONLY USED ONCE. CLEAR BOX INCLUDED LIGHTWEIGHT AND FLEXIBLE: The Nike Flex 2017 RN Men’s Running Shoe helps keep you light on your feet from start to finish with an engineered mesh upper and lightweight, flexible outsole. Engineered mesh upper is breathable where you need it most Flywire technology delivers midfoot lockdown Dual-density foam midsole/outsole for lightweight comfort Rounded heel promotes natural range of motion Rubber pods at the toe and heel for durable traction Tri-star outsole pattern enhances flexibility