Koala Adjustable wine aerator for bottleAerate wine instantly while pouring it into a glass! This adjustable wine aerator is made of high quality transparent acrylic material, which does not alter the temperature or flavor of the wine, and silicone that ensures it attaches directly to the wine bottle mouthlike a stopper. Its operation is very simple, it has an aeration hole that you can open (ON) or close (OFF) depending on the wine you are serving. To aerate the wine, you must have the