FABRIC Yak leather GORE-TEX is a highly breathable and 100% waterproof membrane which is exceptionally thin and has over 9 billion pores per square inch. We integrate a GORE-TEX membrane into our uppers before carefully sealing them. Using this technology enables us to create comfortable shoes that are guaranteed to keep your feet dry. BIOM NATURAL MOTION technology is based on the natural shape and movement of the foot. It encourages the muscles and ligaments in your leg and foot to strengthen with every step making your movements more efficient and smooth, and allowing for a more powerful push-off. BIOMs key elements are reduced seam construction, an anatomical last which is designed to match the curves of your foot, low-to-the-ground construction, and easy flexibility. These features create an embracing glove-like fit that frees you to move with barefoot ease and efficiency.