The Levitron Revolution creates levitation via magnetism. The base unit features magnets in each of its four corners. The processor inside continually adjusts their strength to keep the magnetic disc centered and floating.
The Levitron's processor constantly adjusts itself (1,000 times per second!) to keep the magnetic disc centered and aloft. So, if you add weight to it, spin the object on top of it, or bump it, the disc will remain floating.
As an addendum to the legal opinion linked above, we note that the very first Claim of the Hones patent - which describes a base having a"polygonal periphery and a substantially planar first surface" - is encompassed by Claim 12 of the Harrigan Patent, which describes an arrangement where the base "comprises at least three discrete magnets disposed about said first axis, each said discrete magnets being disposed with the axis thereof inclined at the same angle to said first axis, with the same radial angle there between." The legal language aside, what Harrigan discloses here is that a polygonal arrangement of separate magnets can be utilized as a base. You may to see a photo of a levitron base prototype that Martin Simon constructed to test this scheme. It worked. And not only is a circle, technically, an infinite polygon with a "polygonal periphery," but the tops of the array of cylindrical magnets can, indeed, define a "substantially planar first surface."