1990 Clad Proof Set U.S. Mint Original Government Packaging OGP COA The 1990 Clad Proof Set from the U.S. Mint includes coins with a composition of copper-plated zinc and copper-nickel. This set is uncirculated, struck in proof quality, and comes with original government packaging and a Certificate of Authenticity from the U.S. Mint. The set contains coins of denominations 1 cent, 5 cents, 10 cents, 25 cents, and 50 cents, all minted in San Francisco in 1990. The coins are ideal for collectors looking for pristine coins with a government guarantee of authenticity. 71326-42x2 71326-188