Inside the neck of this pourer is an hourglass-like narrow passage-way called a venturi pipe. The venturi pipe increases the speed of wine flow and creates a vacuum that draws in air through the small vent hole. In addition, a special stainless screen disperses the flow before it leaves the pourer." Beverage Factory
Wine pourers like the one above promise to decant your wine, while it is being poured into your glass. I’ve used this pourer for a couple years now and I can’t say I’ve noticed an appreciable difference. When it comes to decanting, my rule of thumb is to pour some into your glass and if you find decanting will further enhance the experience by all means do so. Back to this pourer, which I really liked when I first started using it but after a while it started to drip around the base and just a warning it does not fit all bottles the same. This pourer may actually fall into your glass, so be careful and crack delicate crystal.
"Serve wine with a touch of elegance. The Metrokane Velvet Wine Pourer with Stopper pours smoothly without drips. The stopper seals wine air-tight, preserving opened bottles of wine so that you can enjoy them later on. The pourer features an easy-grip velvet finish in black." Beverage Factory (no aeration value)
This one I liked quite a bit and it does not leak or dribble around the edges. I would recommend getting more than one. From my experience, at least 4 are recommended, the ratio I go with is 2 for white wines and 1 for red and 1 for a Port or a late harvest bottling. The thinking on this for the whites is you may start off with an aperitif of white wine or the appetizer. You simply push in the stopper and off to open the next bottle. While you will most likley finish the red, you can now feel free to tuck the white away. No fuss, no muss.
They also are great to have for your dinner parties, as they you will get nice even pours and your guests will appreciate wine not dripping on thier hands or sides of the glass.
The same can be said of after dinner wines like Port or a dessert wine which you may not finish in evening. With this pourer as eluded to above you can seal the wine back up and put back in storage with out a leak.They work very well!