Design: Added puffs to the heel that are visible on the outside of the shoe and immensely comfortable around your Achilles on the inside Touch points at the tongue create a natural feel as you take off Foam midsole delivers a softer, smoother ride than the Revolution 6 There is a little more room in the forefoot as well, so your toes don't feel cinched or pinched Durability & Traction: The outsole sports a generative traction pattern that combines with reassuring rubber lugs gives you grip when going uphill or downhill