![](http://cdn.allbirds.com/image/upload/f_auto,q_auto,w_375/cms/1UMPlepZEM6CPOUOtvFRLv/4fc13d4afabf5a68f511562adec511c9/TL-M-BTF-Mobile-01.png)
Tree Upper
Silky And Breezy
Our proprietary knit feels silky smooth, breathable, and pleasantly cool thanks to eucalyptus tree fiber responsibly sourced from FSC® Certified forests.
![](http://cdn.allbirds.com/image/upload/f_auto,q_auto,w_860/cms/5hTIfMzFC2FwL6fw3bNLx5/c8c9da13c730b13814d470e1b809becc/TL-M-BTF-Desktop-01.png)
![](http://cdn.allbirds.com/image/upload/f_auto,q_auto,w_375/cms/2HXtmXIE1fXJX0evCAnVVX/30f256c47f0af3bf47961a82dc6193b5/TL-M-BTF-Mobile-02.png)
Low-Density Sole
Light On Your Feet
Expertly cushioned, our proprietary foam with an S-curve tread makes the lightest sole possible and mimics the anatomical flexibility of your feet.
![](http://cdn.allbirds.com/image/upload/f_auto,q_auto,w_860/cms/6Djzb78Tr1dBZahu3sJu5w/dc56a21b48341cf3b4195ef7549c1c2b/TL-M-BTF-Desktop-02.png)