The Gore-Tex® membrane is completely impervious to rain, sleet and snow, while allowing perspiration to pass through it. A single square inch of the Gore-Tex® membrane contains 9 billion microscopic pores - each pore is 20,000 times smaller than a raindrop but 700 times larger than a molecule of water vapor - so while water can't pass through the fabric, perspiration can.
The North Face uses Gore-Tex® fabric in shoes, not only because of its waterproof / breathable capabilities, but because it is rigorously tested for durability. Abrasion and flexing tests are done in laboratory conditions that exceed even the most extreme weather environments.
Perched on the cutting edge of technology, The North Face introduces Gore-Tex® XCR® fabric, a revolution in breathable fabrics. Designed in conjunction with W.L. Gore & Associates, Inc., Gore-Tex® XCR® fabric (extended comfort range) is durable, waterproof, windproof, and extremely breathable. The bottom line: unparalleled comfort. Gore-Tex® XCR® fabric increases the breathability of your footwear without compromising waterproofness or adding weight.
