They are one size fits all but I and I’m sure some other Crohn’s patients have very small wrist. I can’t speak for everyone and I’m not saying my bands don’t fit but the could be a little tighter seen as there open ended and can stretch out plenty but you can’t make them smaller. I still love my awareness ribbon bracelets and plan on shopping more from this site , I love the fact that profits go to cures and awareness. Also the site is easy to use , the staff that I have talked too and have helped me are very friendly and helpful, and when you do make a purchase you can track the shipment easily and you receive your order in a timely fashion. Great work , you are all appreciated by me and I hope others as well.