1 Gallon Carboy Screw Cap w/ Barbed Fitting

This is a cap that screws onto the 1 gallon carboys. The barbed fitting can be used to to connect a blow off tube (3/8 in.) into a glass jar instead of using an airlock.

It is intended to be used with something like the link below. It has a very good description on why you'd want a blow off tube vs an airlock. Check it out!

http://www.thingiverse.com/thing:42617

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Also consider joining the Home Brew group on Thingiverse:
http://www.thingiverse.com/groups/brewing/about