The Nintendo DS Duo Slot Is an expansion device created by GamerAvenue Co. which is usually used to place updates in the game. There are two Versions, One which is compatible with an Older device which uses the GBA Game slot, The other version (Used for the more recent versions) uses Local Wireless Connection, Opening a Pop-Up to Update the User's DS Game (If it is Compadible). The Media for the DS Duo slots are Duo Cards, Similar to DS Cards, Only at a Smaller Scale to fit the Device.