I recently ordered a pair of Arthur thongs in size US11. On receipt I found them to be too large, and contacted Viviblu for an exchange for size 10. This was extremely easy, thanks to the responsive Customer Service person Angela, and my correct size thongs arrived in a few days. On trying these out, I found them to be extremely comfortable and look forward to giving them extended use. Full marks to Viviblu for an excellent product and great customer service!