This storage system is designed to hold the base game, Mountains of Madness (big box expansion), Under the Pyramids (big box expansion), Forsaken Lore (small box expansion), Strange Remnants (small box expansion), and Signs of Carcosa (small box expansion). It is designed to hold sleeved cards (premium FFG sleeves). It does this by using the (3) big boxes to store (3) main trays. (2) of the trays are used to hold all the cards along with inner trays to hold bits. The third tray lays on top of all the boards and mauals and holds the player standups, cards and Ancient One cards (along with monster tokens). All in all the system is comprised of seven trays. NOTE: It is designed to hold all 6 expansions. Therefore it requires use of the boxes of the big box expansions. It could be used without the small expansions but it best served when using it for all 6 expansions.