The trick its self is fantastic but it does require you to follow the directions very carefully and a a lot of materials that you will need to buy and unlikely to have at home. i was satisfied just paying for the answer because I have to assume a mechanical engineer came up with the design as its very very clever. If you don't mind spending 20 bucks for materials and can follow the directions easily then its absolutely worth the money. Even if you don't do the trick to see how he came up with it is pretty ingenious. I do wish there were better camera angles and downloadable instructions because the filming isn't too professional and difficult to see in parts.