The 1986-S Mint Proof Set is a highly collectible coin set produced by the U.S. Mint in San Francisco. This set includes coins with a copper composition, struck in proof condition with a fineness of 0.917. Each coin is certified by the U.S. Mint and comes in its original government packaging (OGP), making it a valuable addition to any coin collection. The set is from 1986 and contains coins that are uncirculated and in pristine proof condition, making it a sought-after item for numismatists and collectors alike.