King Of Tokyo Insert v2: - Rules of Play says:
Insert compatible with King of Tokyo®, including the Power Up!® and Halloween® expansions, as well as the King Kong®, Cthulhu®, Anubis®, and Cybertooth® Monster Packs®. 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.