The box that I received is "Set 1" in the official card game series. It contains three decks of 64 cards each: Over the Rainbow, Speaking Out, and Lost in Space.
Each deck is a themed game of Go Fish containing 16 sets of 4 cards each. However, the cards contain advanced vocabulary words from Reader's Digest Word Power columns. The four facets of each card are: Definition and Part of Speech, Word Origin, Synonyms, Fill in the Blank, the latter of which is an example sentence in which a blank indicates where the word would go.
On your turn, you ask for a card whose [insert facet] is [insert facet's description], e.g. "I would like a card whose synonyms are abandon, abdicate, discard, throw away." If the player has a "Jettison" card, he gives it up. The rest of the rules are Go Fish.
The box includes a supplementary color guide with pictures and further explanations for each word.