Pokemon TCG: Hidden Fates Pin Collection Mewtwo/Mew - Rules of Play says:
Show your Pokémon pride with a collector's pin featuring the Legendary Pokémon Mewtwo or the Mythical Pokémon Mew! You'll also expand your Pokémon TCG roster with awesome foil promo cards featuring one of these amazing Psychic-type Pokémon. Plus, each collection includes three booster packs from the special Pokémon TCG: Hidden Fates expansion!