Military Challenge Coin. Challenge Coin – US Navy – Naval Special Warfare Unit 1 – Task Force 71. Coin is maintained in a. See pictures for visual details. Photos taken with and without camera flash. Some photos may show currency, soda cans and/or props along with item(s) for size representation only. Items are unique, cool and sometimes random, just like our universe. Orders are often sent using acceptable, clean, recycled envelopes, boxes and materials. The ad price is our price. Thank you for looking.