My husband bought a few different pairs and missed the return window on these ones. Never worn, still in box. Currently sold online at Reebok. NANO X3 SHOES VERSATILE FITNESS SHOES WITH A SUPPORTIVE BUILD Believe it or not, there's a training shoe you can actually run in. Meet the Nano X3 training shoes with the all new Lift and Run Chassis system. A dome-shaped heel piece compresses under load when lifting to create a stable platform, then softens when you push off to run. It all rides on award-winning Floatride Energy Foam that gives you lightweight cushioning to make that run the easiest part of the workout.