This is not the Big Box, only an extension for it. You need the Big Box to use this. This extension and accompanying insert extends the Big Box to hold all the most recently released content for Terraforming Mars. Contents: 1 Extension Piece to expand your Big Box 4 cardboard pieces to build support in your Big Box Lid 1 Insert to hold new game material 2 Deck Boxes, each able to hold approximately 100 sleeved cards. 1 Insert Lid to replace the old lid that held the game boards