If you want to shell out some serious coin during the next promotional campaign, these 1.75" zinc Challenge coins will do the trick! They rival in quality to our brass coins at a lighter weight. Originating during World War I, Challenge coins were issued to battalions as symbols of camaraderie and unity, and later they were used as a way of verifying membership in clubs, groups and military units. They are now commonly given away at military and DOD meetings as a token of appreciation. Customize this memorable keepsake with an imprint of your choosing.