The 1964 US Mint Proof Set is a valuable collection of uncirculated silver coins struck in proof quality at the Philadelphia Mint. This set includes three 90% silver coins in their original envelope and cello flat pack, making it a sought-after item among collectors. With U.S. Mint certification, this set is a cherished addition to any coin enthusiast's collection, showcasing the craftsmanship and history of American coinage. One of the nickels in the set is toned.