The ring surface width is about 6MM
Inner diameter: adjustable between 16.9-18.3MM,
Finger circumference: adjustable between 53.1-57.5MM, suitable for boys.
Silver reacts with sulfide to turn black, so please remove the ring when you are in hot spring or bath with sulfur soap.
Please keep the silver ring sealed when you are not wearing it. Silver will oxidize and turn black after a long time, but you can use a little toothpaste to make it clear and bright.