The goal is obvious and what you have to do is obvious too. You have to unscrew the screw so that the red stick can be taken completely out of the bottle, which would free the marble. Easier said than done...!
This puzzle does not require a lot of steps to be solved but it's tricky, and you know that before you try this puzzle, just because it's a Strijbos' :-)
The first step is clever. The next step you will be tempted to act like as you did with the 1st step and you will notice that it does not work. It's normal, you just don't do the correct thing. Have a careful look at the red stick, perhaps that may help you. Anyway, you don't need any external tools.
Be gentle with the bottle, it's in glass and glass can break...
|Solved finally!! With a lot of perseverance|
If you like bottle puzzles or if you intend to complete your collection of bottle puzzles, I advise you to buy it when Wil Strijbos has some to sell (they are pretty scarce because it seems that Wil does not make a lot of them). I keep hoping that Wil will make again some of the other bottle puzzles, my collection of them is not completed yet :-(