The oil-impregnated leather exterior has a wax topcoat to stay soft and repel water. The use of a nearly century-old technique called siping (cutting thin slits across a rubber surface to improve traction) has resulted in our custom no-slip, shock absorbent rubber sole. Full glove-leather lining delivers buttery soft feel, superior breathability, and eliminates pressure points. Padded tongue and collar Triple-Density memory foam insole, topped in silky smooth leather. Easily removed if you wish to use your own orthotics or need to replace. Designed in Mill Valley, CA. Handcrafted in Portugal.