"Treadlite by UGG" UGG shoes. The new Treadlite sole is comfortable. The main ingredient in the material is rubber, which provides maximum elasticity, cushioning, and rebound. This dynamic effect increases the “bounciness” of the sole, which means you’ll have a spring in your step every time you wear your new UGG boots. You have always trusted UGG boots to be soft, warm, and cozy, and the Treadlite sole takes that reliable comfort to the next level. Never worn still new!