This holder is made as a safer way to ship rounds and has built-in separators to prevent the coins from contacting each other. The holder fits 20 rounds in sizes ranging from 38 mm to 40.6 mm. Note this is made from polypropylene and is not recommended for long-term storage as it is not air-tight and may cause tarnishing. This is designed for shipping coins or medallions without them contacting each other. For longer-term coin storage, see our other listings!