BioWorld Chad Barefoot Transition SandalsStarter Barefoot Sandals with Vibram Soles BioWorld has quickly made the top of the "barefoot shoes you need to own" list. Utilizing a 4mm rubber Vibram sole, these Chad transition sandals boast unmatched durability, flexibility, and lightweight design. The high quality construction of their vegan material uppers ensures both comfort and longevity. These transition sandals provide thicker sole than the standard Bioworld sandal to reduce fatigue for