This tumbler is the Cadillac of tumbling. It does have a higher price tag than a traditional rotary tumbler, but the pros that use it say they wouldn't use anything else other than a magnetic pin tumbler!

Tiny pins that are a mere 0.5mm in diameter are able to get into cracks and crannies that traditional rotary tumblers simply cannot access.

The clear container remains stable on top of the machine - it doesn't move.  Inside the base of the unit is a spinning set of magnets.  The pins up in the clear container resting in water - they follow the magnets, making them fly around inside the water.   Your creations won't be moving as fast as the pins, therefore the pins collide with the pieces making microscopic "hits" on them thus "polishing" the surface.

Notes from a Pin "Tumblerologist"
One of the great things about a pin tumbler is how fast they can work.  Typically, you can run it for 10 minutes on the average piece.  However, I strongly suggest you try shorter times, as short as 5 minutes to see the effect you get because polishing can be a matter of how MUCH you polish to get a desired effect.  All you can get isn't always the best look!  The other extreme would be 20 minutes but you may find there isn't much difference in that and 10 minutes in most cases.  Suggestion...  Put a piece in and check it every 5 minutes and that will benchmark the effect you get.  Keep in mind that the starting condition of the piece will dictate the time it takes to polish a piece.