Oofos, OOriginal Sandal. Help reduce stress on your lower back, knees and feet! Your feet, back and knees will thank you. Lightweight OOfoam upper with bold graphics is moisture and bacteria resistant . Thong style sandal with soft, conforming toe post for an easy on and off. OOfoam biomechanically deigned footbed with arch support and impact absorption for all day comfort. OOfoam absorbs 37 percent more shock than other materials. 1 1/4 inch heel. OOfoam textured outsole. Sizes shown are Men's sizes - Women should add 2 from their size (Ex. Men's 5 = Women's 7)