Review on Twin Bubble Airlock and Carboy Bung (Pack of 2): Superior Quality Fermentation Accessories for Home Brewing and Wine Making by Anna Coleman

Almost what you would expect. These plastic locks work great in standard sized bottles. You should really wedge them the first few times, but they should be tight to create an airtight seal (and this has been the case on all of the projects I've used them on). A few things to note: - My gateways look exactly like the picture, no red caps or other details. Putting them in a food grade disinfectant (like SanStar) will help reduce the number of bugs that want to swim around them and allow the liquid to flow back into everything you do. it won't ruin it (a friend of mine accidentally broke a beer). - Check which cork is suitable for your container, there are different sizes. I've only used them on 5 and 6 gallon glass bottles.