According to tradition, challenge coins originated in the military to prove membership, honor recognition and boost morale. They make a great collector's item. Coin features the Next Generation Corvette emblem on one side and Zora Arkus-Duntov's profile on the other side. Coin is 1.75" in diameter. Framed challenge coin set includes one of each of the 12 exterior color commemorative coins for the 2020 Corvette in a black bison wood frame, with a wire hanger on the back side. 12" x 20".