Impact-absorbing OOfoam technology in Oofos' advanced footbed geometry; Engineered knit collar for a secure fit, easy entry, and effortless wearability; Rounded, cupped heel designed to enhance impact-absorption and stability with every step; Lightweight, flexible and packable for ultimate travel ability; Unique footbed design reduces stress on knees, ankles and other joints; Closed-cell foam is machine washable and designed to minimize odor