The Reebok ZPump Fusion: The sneaker that adapts to you - every time. The Reebok ZPump Fusion Pumps up and provides runners with a locked-in custom fit for a great feel as you rack up the miles. Pump technology is an air-filled cage that pumps up and molds to any runners foot for a locked-in custom fit, while the Fusion sleeve is a lightweight and seamless compression sleeve that fuses The Pump technology to any runner's foot. Add these technologies to a Zrated outsole inspired by high-performance tires for control in and out of turns, and you've got an advanced running shoe that's ready to take on the miles with style.