Genuine OEM Nintendo 64 Expansion Pak (model NUS-007) that upgrades your console's memory from 4MB to 8MB. This official add-on is required for certain games like Donkey Kong 64 and The Legend of Zelda: Majora's Mask, and unlocks high-resolution modes in others such as Perfect Dark. This is an authentic used unit tested and working; it is region-free and compatible with any Nintendo 64 console worldwide.