The 1955 US Mint Silver Proof Set includes 5 uncirculated coins with a composition of 90% silver and a denomination of 50 cents. These coins are struck in proof finish at the Philadelphia Mint and are certified by the U.S. Mint. The set comes in a black acrylic holder, with some toning evident on the coins. This collection is a valuable addition to any coin enthusiast's portfolio, showcasing the craftsmanship and quality of the United States Mint in 1955.