This plastic carbonation cap has been designed to suit soda bottles, coke bottles, and FermZilla lids. If you have a keg system you should have at least a couple of these as they are so useful.
Note: It is a multi post, so it will take both gas or liquid if you want to change it up.
NOTE: The duotight fitting shown in the photos does not come included. If you want to attach the duotight fitting on the back of this fitting then you can use the this one that will allow you to attach 8mm OD EVABarrier 4mm or 5mm ID Beer Line.
The thread specification on this product is the PCO 1881 (AKA Coke bottle thread)