Nickel plated challenge coin with standard/smooth flat edge cut and zinc core. Challenge coins originated during World War I; they were issued to battalions as symbols of camaraderie and unity. Later, they were used as a way of verifying membership in a club, group, or military unit. Challenge coins are now commonly given away at military and DOD meetings as a token of appreciation or as a promotional product. If artwork includes specs that is more than 1 color on each side, it is necessary to review file to confirm capability of run and accurate costs.