The N64 Passport is an adapter cartridge for the Nintendo 64 video game console that was released by EMS. Games for the N64 console have region lockout which prevents, for example, a European game running on a North American or Japanese system. The N64 Passport cartridge sits in between the system and the game allowing players to play games from different regions. It requires a 'boot' cartridge (of the same region as the system being used) slotted into the back of it, and a game from a different region on the top. There are three different versions, with the N64 Passport Plus III being the final version released. The 'Plus' versions also have an Action Replay which allows custom cheat codes to be used.