Genuine and authentic Chairman Joint Chiefs of Staff Admiral Mike Mullen Challenge Coin-Presented by Admiral Mike Mullen 17th Chairman Joint Chiefs of Staff CJCS REAL Challenge Coin. Condition is Used. Shipped with USPS Ground Advantage. Approx 2". Used condition with signs of wear consistent with carrying the coin during service. Offers and questions are welcome. We usually ship within three days or sooner. See pictures and any comments for more on condition.