I purchased my usual Fit Flop size but they swam on me. The exchange process to size down was straightforward and professional ( a huge step up from their old customer service which used to be pretty woeful). Received the smaller ones very quickly and they fit perfectly. As a I have a bad knee, a strap around the back would be a great addition and provide some extra support. Overall very happy and they are a bit funkier than my other FF's.