This all stainless male gas ball lock cap that fits 32mm plastic PET growlers and Tap A Draft bottles. This allows the PET Growler or Tap A Draft  bottle to be charged with C02 from any female ball lock gas fitting. Suitable for carbonating cold beverages in the bottle including cold water. 

This is ideal for adding a bit of charge to a PET growler after you fill it, as no matter how carefully you fill a PET growler from a draft system, some C02 carbonation is lost. Great for serving draft beer away from the keg. Also use to charge Tap-A-Draft bottles with C02 once they are filled. CAUTION: For use with plastic bottles only.