A classic little trick that's been at the top of the popularity list forever because it's SO EASY yet SO BAFFLING!
Place the little ball on top of the vase. Cover it with the cap, and instantly remove the cover to reveal- the ball has vanished! Just as quickly, as soon as you put the cover on the vase and take it off again- the ball has reappeared! Take the ball out of the vase, put the ball in your pocket, put the cap on the vase, lift the cap off- the ball has invisibly returned to the vase!
This is so easy, it practically works by itself! And you can repeat it immediately. If you can put the cap on the vase, you can do the trick!
THIS VIDEO DEMO IS FROM THE MANUFACTURER:
A description of the Ball Vase principle appears in a French mathematics book published in 1693 by Jacques Ozanam.