Know Your Fellow Browncoats! Because you never know when the Alliance might be running an undercover sting operation, it's a good idea to carry one of these handy forms of Browncoat ID. The Firefly Keep Flying Challenge Coin features an intricately detailed view of Serenity in relief. The flip side displays the colorful Independents Army symbol bordered by the remembrance, "Never forget Serenity Valley." Diameter measures approximately 1 1/2-inches. Ages 13 and up.