Clank! Insert: - Rules of Play says:
Insert compatible with Clank!®, and the Sunken Treasures®, The Mummy’s Curse®, Gold and Silk® and Acquisitions Incorporated: Upper Management Pack® expansions. The design provides both efficient storage and improved game play. Many of the trays can be utilised during the game, and they greatly aid set-up and clear-away times. The boards act as a lid on top of the trays.