The 2020 Lincoln Shield Penny without a mint mark is a rare error coin that is highly sought after by collectors. This particular coin is made of copper with a fineness of 0.95 and features a red color. Despite being part of the business strike type, it is circulated and ungraded, making it a valuable addition to any coin collection. The off-centering of the coin adds to its unique appeal, further distinguishing it as a rare find for collectors of US coins.