Silicone Stopper, 2 PCS Airlock Stopper, Carboy Airlock Stopper with 8mm Hole, Silicone Plugs for Homebrewing Beer/Kombucha (#10)

I bought these to replace the bungs that came with the airlocks I bought. The description on the airlocks/bungs said they fit standard 6 gallon carboys, I didn't realize the PET carboys had a wider opening, so I needed larger replacements. The reason for the 4 stars is that, while these fit the mouth of the carboy great, the hole for the airlock is extremely tight. I tried several different airlocks and several bungs, had issues with all of them. It's easy enough to get the airlock in if you wet it with sanitizer first, but once that dries up and you try to remove the airlock after a couple weeks ... yeah, I broke an airlock the first time. They're honestly a little spendy, but I think they'll last me a while. Not sure if I'd buy them again, haven't had them long enough to see how durable they are, but I'm overall happy with them.

The stopper has the outer mold line of a #10 stopper, so it fits in the hole in my fermenter. However, the hole that is drilled out in the middle of the stopper is WAY too small for a standard air lock. I didn't give it lower than 4 stars since the ad says it's an 8mm hole. I just assumed they knew what they were doing--not so. Not sure what they drilled the hole for, but it's not for a standard air lock. I can force it in, but it will eventually break the air lock, just a matter of time. My other stoppers and grommets have 9.25 and 10 mm holes respectively.

I bought these to replace the rather cheap one that came with a Chapman fermenter. That one turned brown after the first use while these still look new after several uses.

Great quality but doesn’t stay in a glass car boy. I had to engineer a work around to keep it from being popped out when I added the airlock but worked perfect in the bucket top.

Arrived quick and fits my 6 gallon plastic carboy fine. Just have to be careful to only press it in till snug or it would be difficult to remove.

Great stoppers. The silicone is more resisant to staining, which is really nice compared to traditional rubber ones. Only issue: airlocks tend to seize in them a bit more easily.

They were a little on the hard side but work like a charm

good