These capsules are Made in the USA from an acrylic plastic with a non-yellowing agent. This process results in a final product that is hard, crystal clear, and smooth to the touch. The cover and base close together firmly to form a perfect seal. The capsules are PVC Free, archival Safe are suitable for extended periods of long term coin or bar storage. The Rings are made of an inert cross linked polyethylene. The rings secure the coin in the holder. They will create an additional barrier against air contamination and also presents an attractive border to accent the coin. *Some coins are thicker than the inside depth of this capsule, but can still be used in this holder. You may experience a small gap between the top and bottom pieces that is about the thickness of a fingernail.