OOFOS OOriginal Recovery Sandal - Women’s and Men’s The Original Recovery Footwear. Finding Your Size - For your perfect fit, consult the “size chart” link above. Wear a half size? In general, we recommend that women who wear a ½ size size UP, and men who wear a ½ size size DOWN OOriginal - The one that started it all. The OOriginal recovery sandal established the proven foundation of proprietary OOfoam technology + patented footbed design that remains our top-seller OOfoam Technology - Our revolutionary OOfoam technology absorbs 37% more impact than traditional footwear foam materials to reduce the stress on your feet, joints & back. Plus, the closed-cell foam is machine washable and designed to minimize odor Patented Footbed - Our patented footbed cradles and supports arches to reduce energy exertion in the ankles by up to 47% compared to competitors’ footwear. So walking is easier. Recovery is faster.