Great running shoe. Ordered the wrong size. Very comfortable and lightweight. Hoka website description: What do you get when you cross the comfort and support of the Mach with a propulsive Pebax® plate? You’re looking at it. A pace-pushing trainer built with high-rebound cushioning; the new Mach X is supercharged with a layer of PEBA foam that’s 34% more resilient than the Carbon X3 foam. Softer and snappier than ever before, this adaptable trainer is comfortable enough for endurance efforts and responds equally well to pace increases.