The Topo Phantom toe box is designed to let your foot have plenty of room for your toes to spread and splay. A secure fit through the heel and midfoot allows the shoe to move with your body. The 5mm stack height makes the Phantom Topo’s most cushioned road running shoe. Strategically placed rubber adds traction and durability where needed; Zipfoam™, a proprietary new lightweight midsole compound keeps this shoe springier with more rebound than traditional EVA. A breathable engineered mesh upper with lightly printed overlays and an external TPU heel counter help keep the runner secure over the platform.