2" black nickel plated Khallus Limited Edition 2020 Challenge Coin. The idea of the challenge coin is believed to go back to World War 1 where commanders presented their troops with a special coin to express their gratitude. Since then, challenge coins have been a fundamental part of military and government service. Dated 2020 with VERY limited quantities available, order one while you can. Intended to be handed out in person from the band, but limited quantities can be purchased online.