The product is a collection of 31 government issued proof sets from the years 1968 through 1998, all containing proof coins. These sets are minted in San Francisco and certified by the U.S. Mint, ensuring their authenticity and quality. Each set includes coins in uncirculated condition, struck as proof sets in the United States. This comprehensive collection is a valuable addition to any coin enthusiast's collection, showcasing the beauty and craftsmanship of U.S. coins from the late 20th century. Thank you for looking.