The 2017-S United States Mint Silver Proof Set 10-Coins OGP NB91 is a collectible set of US 90% silver coins minted by the U.S. Mint. This set includes 10 coins with a fineness of 0.900, struck as proof coins. The set is not graded and comes with original government packaging. Each coin is composed of silver and is a valuable addition to any coin collection, particularly for those interested in bullion coins and United States coinage.