5 and I decided to buy size 10, but it was tight. I wanted to add a towel bar holder to a built in cabinet in my kids bathroom, next to the sink. However, after a few adjustments with the filling to make to his liking he actually said it helped, high praise indeed, Im amazed! I love that these Keens for kids in a six fit my feet perfectly! They are indeed very fast. Price point is too good to be true. It’s rustic-chic just like the pictures show. This was crucial for me because I get impatient with the slow rate of natural cell turnover, and I end up picking at my bottom lip and sabotaging the whole healing process. However, its still perfect and I highly reccomend it. Otherwise, the product works well for now.