Allbirds Women's Tree Loungers Rugged Beige (Rugged Beige Sole) Size 9. Keep things light and breezy with these slip-on sneakers made with lightweight eucalyptus tree fiber that gives you maximum comfort in a minimalist design. Best For: Walking, everyday wear Thermoregulating Material: Lightweight, breathable eucalyptus fiber provides next-level comfort Versatile Design: Wear-with-everything classic style, great for travel Where It’s Made: Vietnam.