In the market for a traditional collector's items that will be cherished forever? These 2.5" brass challenge coins are just what you need! 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. Make these memorable keepsakes your own by adding a customized imprint of your brand logo or message.