Pokemon TCG: Power Partnership TAG Team Tin - Rules of Play says:
A powerful partnership makes for a great TAG TEAM—and good partners fight a little harder to win together! Choose the deep history and psychic power of Mewtwo & Mew-GX, the steely nerves and focus of Lucario & Melmetal-GX, or the game-changing attacks of Garchomp & Giratina-GX in the Pokémon Trading Card Game: Power Partnership Tin. Each of these fantastic tins contains a standout TAG TEAM Pokémon-GX, their bond tried and tested in battle! You'll also get four Pokémon TCG booster packs and an impressively sturdy metal TAG TEAM GX marker.