These "Suspensions" are on the left 10" tall with 3 strings at $300, then 24" in the middle with 4 large magnets for $1500, then on the right is the 16" tall verion with 4 strings at $500. Those are high powered industrial rare earth neodymium iron boron magnets on the ends of the cords, and also on the frame of the circle, to hold the magnets in place by magnetic force alone. I am frequently out of stock on these very popular items. If you are ordering one as a gift, I suggest ordering 2-3 months in advance. A larger version is also available, and was seen in the cult classic movie "Austin Powers- The Spy Who Shagged Me," in Dr. Evil's lair.