New style comes with refreshed design and updated construction to maximize comfort The Tree Runner NZ uses Allbirds' industry-leading library of natural and recycled materials to deliver a superior comfort experience. Like its predecessor, the Tree Runner NZ's upper is made with a tree knit fiber blend, beloved for its breathability. This cool, soft and lightweight material combines TENCEL™ Lyocell with recycled polyester, delivering durability that can withstand whatever your day demands. The Tree Runner N ...