This 1991 United States Proof Set is a must-have for any coin collector. The set includes a variety of coins, all struck in proof quality. The composition of the coins is a combination of copper and nickel, and they were minted in San Francisco. The set is uncirculated and ungraded, making it a great addition to any collection. The coins also come with certification from the U.S. Mint. Don't miss out on this opportunity to add a beautiful set of coins to your collection.