Both styles of Runners have the same minimal design and incredible comfort, but the difference lies in their material innovation. While our Wool Runners are made of merino wool, the Tree Runners are made with Tencel, which is created from Eucalyptus trees. Our Tree Runners are better equipped for warm temperatures, as they are extremely breathable and light. You can also wear them without socks, similar to our Wool Runners. Like our wool runners, they also have our castor bean oil made insoles for maximum comfort in every step.