The Greninja ex Box is one half of a pair, sold alongside a Sylveon ex version at the same £21.99. Both are four-pack products built around a foil promo of the named Pokémon, and both include an oversize foil version of that same card. Retailers list the two interchangeably more often than they should, or simply ship whichever is in the warehouse, so check that a listing actually names the Greninja version if that is the one you are after. Four packs of this set is 24 cards, every one foil, with a guaranteed Pikachu in each. The promo is the reason to pick this over a bundle. The oversize card is display material rather than anything playable, so treat this as buying the Greninja with packs attached. Of the two promos in the pair, Greninja has been the easier to find at retail, which makes it the better bet if you want one at RRP rather than either specifically.