Sympatex higH20ut has all the benefits of ALL WEATHER, but is 120% more breathable than conventional membranes. When you are more active, or in warmer climates the foot can produce more perspiration then can be transported away, leaving your feet feeling clammy & cold. However with Sympatex higH20ut the additional moisture allows the special molecular structure of the higH20ut membrane to swell, this creates a higher capacity for perspiration vapour to be transported away from the foot. The liquid perspiration does not bead on the lining but is absorbed & spread out over a larger surface area allowing the moisture to evaporate quicker, leaving your feet dry & comfortable. Sympatex contains no halogens or solvents & is classified as an environmentally friendly material by the independent Hohenstein Institute (Germany).