I have very skinny fingers and after reading various reviews to size up on this design I opted for a size 5. What I found is a bit odd is the invoice says size 5 but the tag attached to the ring itslef says "6" (?) It fits though that's what it matters lol I plan to wear it on my right middle finger!
By the way I ordered it from Net-A-Porter
They arrived wonderfully packaged and they even sent me a nice black tap measurer in a little pouch as a "welcome" gift. How sweet!!