This was given to me by an acquaintance. I was told it was distributed to those involved as a commemorative item during some event held by the Imperial Family. It came in a clear case, but I discarded the case and stored it in a glass cabinet. It looks clean at first glance, but upon closer inspection, there are spots of what appears to be dirt on the back. Diameter: Approximately 4cm The inscription "24.KGP" is engraved on the back. Please understand that this is a used item.