Half dollars are U.S. coins worth 50 cents, made of a combination of copper and nickel. They feature the image of John F. Kennedy on the obverse side, which was introduced in 1964 following his assassination. The reverse side typically shows the Great Seal of the United States. Half dollars are larger than other common coins, measuring 30.61 millimeters in diameter. While they are still produced, they are not commonly used in everyday transactions. Instead, they are often collected by numismatists or used in special occasions, such as coin rolls or gift sets.