With support inspired by the human spine, the Under Armour Spine Venom 2 will make sure you never back down — even on the toughest runs. Breathable mesh upper with underlying MPZ structure for protection and light weight. UA Spine chassis technology for light, flexible feel without sacrificing support. Micro G foam within the chassis provides rebound and energy return. Solid rubber outsole for full ground contact and traction. Carbon rubber in the heel for durability. Wt. 8.8 oz.