Allbirds Men's Tree Loungers Navy Night With White Sole Size 13 Keep things light and breezy with our slip-on sneakers made with lightweight eucalyptus tree fiber that gives you maximum comfort in a minimalist design. Best For: Walking, warmer weather, everyday wear Thermoregulating Material: Lightweight, breathable eucalyptus fiber provides next-level comfort Versatile Design: Wear-with-everything classic style, great for travel Excellent pre-owned condition, light signs of wear on bottoms (see pictures).