Golf hat with elasticated sweatband. - Tech facts: GORE-TEX® Paclite® Technology features the lightest, most packable fabrics. Durably waterproof, windproof, and extremely breathable. The GORE-TEX® membrane contains over 1.4 billion microscopic pores per square cm. These pores are 20,000 times smaller than a water droplet, but 700 times larger than a water vapour molecule, which makes the GORE-TEX® membrane completely waterproof from the outside, while allowing perspiration to escape from the inside.