Happened to me too, one day my wedding ring flew off my finger and bounces down the hallway. Its ring size was 7.5 US. It couldn't be sized so I had a ring gaurd put in. Recently I was using so much of the ring gaurd (my fingers kept getting smaller) that I caught it on something (from the ring hanging off the back of my finger) that it was dangerous! Hubby let me trade my ring in for a newer, better model - this time one that can be sized. Right now the new one is a 5.5 US and it is really a bit too big, it keeps running around my finger. I think it about 10 pounds or so I will get it sized down again to a 5.