Under Armour Men's UA Spine Venom 2 Running Shoes Synthetic UA Spine chassis technology creates an incredibly light, flexible feel without sacrificing support Micro G foam encapsulated within the chassis delivers unrivaled rebound & energy return Breathable mesh upper with underlying foam & seamless overlays for lightweight structure & support TPU heel counter for greater stability without being too rigid for comfort Full length molded 4D Foam sockliner & collar conform to your foot's shape, eliminating slippage