The 1988 US Proof Set includes 5 uncirculated coins, each made of copper and struck in proof condition at the San Francisco Mint. This set is certified by the U.S. Mint and comes with an OGP/COA. The coins have a denomination of $5 and are a part of the United States coin collection. This set is a valuable addition to any coin enthusiast's collection, showcasing the craftsmanship and history of American currency.