Product Details Designed with a new elevated aesthetic and more springy support, the Tree Runner Go sneakers by Allbirds feature the line's signature breathability for all-day comfort. With a carbon footprint of 4.11kg CO2e, they feature an FSC-certified TENCEL™ Lyocell (eucalyptus tree fiber) upper, a SweetFoam® midsole made with sugarcane-based green EVA, and a castor bean oil-based insole foam. SKU: A10951-DENATN Navy Fabric Lining: Fabric lining Closure: Lace-up fastening Toe style: Round-toe Made in: Vietnam Fits true to size, take your normal size