This is an absolutely wonderful company to work with! I ordered 2 size medium bands that ended up being a bit snug for me to be comfortable. I emailed them requesting a large & the next day, they said, no problem, keep the medium, we will send you a large! Received it & it was perfect. I requested to replace the other medium & that was no problem either. They did send me a prepaid Usps tag to return the 2 mediums which was no problem!