Boutique Zekara - Rieker Tex means that your shoe has a water repellent membrane (a layer found between both the inner and outer material) that keeps feet dry while wicking moisture out.
RiekerTEX membrane | Extra protection and comfort
Rieker TEX Membrane Knee Length Boots | Freemans
Rieker Winterboots, mit TEX-Membrane und gestepptem Schaft Acheter à un bon prix | Ackermann.ch
Rieker Bottines lacées à membrane rieker-Tex | Laura Kent