Parallel-universe box

The Parallel Universe Box or the parabox is a box that was accidentally created by Professor Farnsworth. At first it was going to be thrown into the sun and no-one was allowed to look in it but it was later discovered to have a whole parallel universe inside. Professor Farnsworth in the parallel universe also created a blue box containing our universe. Afterwards more boxes were created containing other parallel universes. The two main boxes were switched so they contained their own universe.