Earth Expanse sandals feature rubber sole, leather insole, and elastic strap runs from the leather toe post around the ankle and is held to the sole by leather straps. Expanse is available in black, bronze, khaki, or silver. Earth Expanse fitness sandals are comfortable, stylish and will get you fit while you wear them. The 3.7° negative heel places your body in a duplication of the yoga mountain pose which is believed to be the perfect body alignment.