Allbirds Women’s Tree Runners Sneakers in Marine Blue (White Sole) Size 9 Condition is preowned. Not worn much. See photos for clear details. Allbirds best seller! A breathable, silky-smooth sneaker made with responsibly sourced eucalyptus tree fiber treads lightly in everything you do. Best For: Walking, warmer weather, and everyday wear Thermoregulating Material: Lightweight, breathable eucalyptus fiber provides next-level comfort Versatile Design: Wear-with-everything classic style, great for travel