I was looking for a pair of slippers to wear around the house that had some support. Last summer I bought my first pair of Keen shoes. I bought the KEEN Women's Clearwater CNX Sandal,Black/Yellow,8.5 M US and the fit was perfect and I love them. I bought them for wearing on my jet ski and pontoon boat but ended wearing them all the time because of the great support and fit. The arch is just behind the ball of my foot and gives great support all day. So, after trying on way too many slippers with no results I looked to Keen and found these slippers. Like others have said, they are more like a slipper/shoe. You can wear them inside or outside. They are comfortable and give great support. I can wear them all day. There is plenty of room for my toes and that is something I really want in a shoe of any kind. I did have to get them in a size 9 however. I usually wear 8.5 - 9 so that was no surprise. I imagine the reason I could wear the 8.5 in the sandal was because there is just a strap by the heel. If you have a high instep they might be a little snug. My instep is somewhat high and I was wearing them around from day one without any discomfort. You can stretch the elastic on the sides if they are a little snug. I can slip them on and off with ease but I do not crush down the back of the slippers when putting them on; I just use my finger or the tab to slip them on without damaging the back. They are a little expensive but I expect they will last a long time and for the support it is definitely worth every penny. Like I said, I love them!I just bought a second pair in celestial blue and noticed that they fit differently. Then I read a review posted on Jan. 7, 2015 by Mom of Two "GNC" who brought it to my attention that there are actually two different styles. My first pair in india ink fit more like a shoe/slipper whereas the pair in celestial blue fit more like a slipper. The celestial blue have a slightly larger opening and more room for your instep. Both can be worn inside or outside. In any case, I love them both!