WAHU is the very first active sole that can adapt its shape to changes in both the wearer's dynamic state; and the external environment, like terrain, temperature or humidity. The sole is equipped with a series of interconnected chambers designed like bellow structures that fill up or release fluid controlled by a miniaturized electro-plunger. This mechanism means the sole's volume can change, which affects how it grips and cushions the foot. Different density levels of natural rubbers ensure different levels of grip, cushioning and breaking strength.