WHIRL-O Trick Deck Set The Physics Of Fun The Whirl-O play set lives at the confluence of magnetism, centrifugal force, and gyroscopic fun. Like a stringless yo-yo, a pair of tops circumscribes the perimeter of a 7" long wand or careens around a 15-3/4" x 11-3/4" wooden game board. (Think competitive top twirling.) Strangely mystifying. Strangely compelling.