Make starting a siphon easier. This airtight flexible cap features two sealable holes, for fitting a 3/8" outer diameter racking cane in the larger center hole. Then blow on the smaller hole to start the siphon without needing to suck the hose. Fits our glass carboys items E57 5 Gallon and item R06 3 Gallon, and also fits all Vintage Shop PET carboys (except Fermonsters).
Also can be used as a blow off cap. The smaller hole accepts 3/8" inner diameter tubing, and the larger hole will fit 1/2" silicone tubing in case you want maximum blow off capacity from both holes.
Notice: Not recommended for use with fruit fermentations, as the larger chunks can clog the blow off, possibly causing a glass carboy explosion.
Does not fit item E40 6.5 gallon glass carboy.
You can be the first to ask a questions.
Carboy cap
The fit on the carboy neck is too loose. I got no action in my airlock. I solved the problem with a hose clamp.
Leaks
I've been using these caps (though the the kind I've been using has a thermoprobe attached and I've noticed that I get no action in my blow off tube while fermentation is going on. I suspect that it leaks around where it wraps around the carboy bung. However, I've never experienced infections from this or anything to that nature. It does the job well enough.