The product consists of four sets of United States proof sets from the years 1961, 1962, 1963, and 1964. These sets are sealed for the years 1963 and 1964, while the sets from 1961 and 1962 have been opened. Still in mint cellophane The coins in these sets are composed of 90% silver and were struck as proof coins in Philadelphia. Each set is certified by the U. Also the cent and nickel are not silver but have the proof strike designation.