Such a necessity that once I received it for Christmas I got rid of the Jumper Pak for good. The Expansion pak holds MUCH more memory. If you have games that need it ask mom and dad night and day to buy you an Expansion Pak. You really have no need for the Jumper Pak. The Jumper Pak is really hard to get out anyway. I had to use a knife to get the Jumper Pak out which cant be too good for the system but what the hey now the Expansion Pak is in and I don't need to worry anymore.