I had previously purchased an aerator you had to hold above the glass with one hand and then pour the wine through it whilst holding the glass and the bottle with the other hand. Inevitably as you stopped pouring the wine or lifted the aerator from the glass you would spill red wine on the table cloth.
The Flow Wine Aerator Pourer however fits straight into the bottle. It hasn't dripped and the wine is beautifully aerated each time you pour the wine from the bottle.
Inside the box there is an extension tube that fits onto the bottom of the Aerator and is inside the bottle but I am not sure exactly what this achieves. Perhaps an explanatory instruction sheet would clarify its usefulness.
However I am very pleased using the Flow Wine Aerator Pourer without this extension tube and it does a great job without any drips.