All Highlights Women’s Core Winter STX Certified leather and recycled materials: sustainable footwear for winter hiking and snowshoeing. Waterproof and dirt repellent. Shaft nestles comfortably against your legs. Made with nubuck leather from the German manufactory Heinen. PrimaLoft® insulation ensures comfortably warm feet. Waterproof inserts prevent water from entering next to the tongue. Climate neutral, made from certified leather and recycled materials.