I thought the sandals were rubber on all sides. It turns out to be foam on the inside of the sole. That is a big problem? no Of course, that makes them more comfortable. But the foam has the ability to absorb everything. They haven't even been out a month and they smell awful. I don't usually have problems with foot odor so I won't be buying it again. Also, the foam most likely won't last as long. But anyway, they deserve what they are so I give them 3 stars. Just very disappointed because they look cool and I wish they were better quality. Even just a little on the cozy side.