THE Reebok THAT ADAPTS TO YOU. EVERYTIME. THE REEBOK ZPUMP merger with PUMP BUTTON OFFERS while running perfect fit The Pump technology features an innovative air chamber system which adapts precisely to your foot shape and thus provides a perfect fit. The lightweight, seam-free uppers 4-way stretch fixes the pump air chamber system on your foot. The inspired ZRATED-high performance tire outsole provides ultimate control while running.