GORE-TEX INFINIUM™️ WINDSTOPPER® is a technology that’s integrated with a GORE-TEX INFINIUM™️ membrane, which is a very thin layer of expanded polytetrafluoroethylene (ePTFE) with billions of microscopic pores. This membrane totally blocks the wind and at the same time allows perspiration to escape to the outside of the garment. GORE-TEX INFINIUM™️ membranes are paired with a durable water-repellent outer fabric to keep light rain from penetrating the garment.