The product is a collection of uncirculated 1955, 1956, 1957, and 1958 proof mint sets from Philadelphia, United States. Each set includes coins with denominations of 1 cent, 5 cents, 10 cents, 25 cents, and 50 cents, all composed of silver with a fineness of 0.9. These sets are ungraded and uncertified, struck as proof by the U. The collection is a valuable addition for collectors interested in the coins issued by the United States during these years.