The 1968-S PROOF SET was minted in San Francisco and has a composition of Clad, with a fineness of 0.999. It is a highly sought-after set with only 3,041,506 pieces produced, making it a rare find for collectors. Certified by the U.S. Mint, this set is a valuable addition to any coin collection, showcasing the craftsmanship and quality of coins from that era.