This pourer was indluded in a gift package, so I don’t know where it can be bought and how much it costs. If you wish to buy something like this, you may search for something called wine pourer or non-spill pourer.
If you serve wine at home, you should know that there is always a drop to fall on the table. Even if it doesn’t drop immediately, it will slowly flow down on the surface of the bottle until it finds the table.
This little thing prevents this from happening. You put this thing on the top of the bottle so that the little spiral part goes into the bottle and that’s all! You may serve the wine now without spilling.