Reebok Women’s Nano X4 Training Pure Grey 2 Vintage Blue Ftwr WhiteReebox Womens Nano X4 Training Pure Grey 2 Vintage Blue Ftwr White The Nano X4 Training Shoes are the lightest and most breathable Nano iteration yet. Crafted with enhanced stability and support, the Flexweave upper and midfoot ventilation panel offer ultralight comfort and increased airflow. The Lift and Run Chassis system provides ultimate stability, while Floatride Energy Foam cushions every stride. Conquer your workouts with Reebox! FLEXWEAVE