The face of the ring measures 17mm at the widest point. On a US ring mandrel the ring falls between a size 5.5 and 5.75, which is a UK size K 1/2 and L. It is fully hallmarked, has been tested, and verified weighing in at 7 grams. There are no problems. This item is pre-owned and there will be ordinary and normal use marks. Comes from a clean, smoke-free home.