In order to eliminate Head Space, I have used: 1) 5 gallon carboys and various size glass jugs to hold the remainder 2) Glass marbles 3) Corks All the solutions have their issues, so I decided to try the All in One Headspace Eliminator (HE). Wine #1: CC Showcase Argentine Malbec that was pitched on May 4, and moved to Carboy around May 13. I did not degass, nor used any clarifying agents. The HE was wet from sanitizing with Starsan. It kept sliding out of the carboy, and would not stay on. Then I got the bright idea of turning on the AIO and drawing a vacuum. That worked .... too well. The HE sealed nicely, and as the vacuum built, the wine started degassing and bubbling. I normally like to keep the CO2 in to help protect the wine. So, I let it degass a little, and then stopped the pump. The degassing stopped, but the HE still held a vacuum (HE bulb still collapsed). Success. Wine #2: MM La Bodega Port. The Port was still fermenting, but now in a 5 gallon carboy (3 gallon kit). Dropping about 0.001 SG per day, if that. Since it was still fermenting, I was happy to degass the port, and boy did it degass. After a while, I stopped the pump, and the HE held a vacuum. Another Success. The next morning, I checked both. The HE in wine #1 was still holding a vacuum. However, the port continued fermenting/degassing, and blew off the HE. So, I put the airlock back on. After a few days, the HE in the wine is still doing fine. Summary: The HE performs as advertised - keeps a seal on wine during bulk aging. The HE is also a great AIO accessory for degassing when you don't want to rack back and forth. The HE is not great for wines that still need degassing, but that is only a problem with new wines. I am happy with the HE. Now, I can get rid of my 5 gallon carboys. But, then I will have to get more 6 gallon ones.