The Mass Storage system allows players to virtually store items, which can be accessed at any time from any survival world, via command.
The Mass Storage system is compatible with most items, but not all. Some items such as enchanted books with multiple enchantments, pocket mobs, and filled shulker boxes will still require conventional storage.
Note that inserting level 2 or 3 firework rockets will result in them being converted to level 1 when retrieved.