The OOlala sandal features revolutionary OOfoam™ technology that absorbs 37% more impact than traditional footwear foam materials to reduce the stress on your feet and joints. This technology aids in the recovery process and creates an incredibly comfortable sandal you can wear anywhere. Features Reduces stress on sore feet, knees, and back Enables more natural motion Minimalist construction for light weight Machine washable OOFOS are made in whole sizes. We recommend sizing up if you’re a women’s half size.