Barely worn. Less Pain, More Bounce Fly through your workout with an energizing bounce and heel-hugging technology. FLUX features supercritical EVA foam, which lasts up to 3X longer and delivers up to 15% more bounce for better energy return. Plus, a sock-like fit and zones of stretch and support create the perfect balance of structure and breathability. Easy on/off design and seamless, sock-like fit—with laces that can be tucked or tied. A heel tab makes it extra simple to slip them on with ease.