These are great indoor slippers with hard soles that will keep your feet dry and ready to run and the fluffy inside really helps to keep your feet warm. I like that they aren't as wide and bulky as Crocs. They sweat a little but the fur comes off so they can be taken off and washed! I like that they are light. I wear size 9.5 tennis shoes and got a size 41. However, my daughter received a different color and had to return it twice to get the right size. In the end she scored 40 points despite wearing tennis shoes 8 or 8.5. Everyone in my family got a pair for Christmas and everyone loved them! Especially men!