Updated with supremely plush collars but engineered with the same full EVA midsoles, breathable mesh uppers and signature Meta-Rocker technology as their predecessors Ultrasoft memory foam collars are designed to conform to a wide variety of ankles and accommodate narrower heels, cradling the Achilles in cushy comfort Open-engineered mesh construction delivers breathable comfort; TPU overlays offer additional midfoot structure and support Internal heel counters provide a supportive, locked-in fit Refined early-stage Meta-Rocker provides a smooth ride Beveled heel design offers a smooth transition and increased durability Rubber outsoles minimize weight and maximize durability Worn a few times, have a ton of miles left in them! Great for your knees