This new model carbonation cap does everything that our old carbonation cap did but this comes with several added features. The post on this unique carbonation cap has been machined to fit BOTH the black/liquid and grey/gas ball lock disconnects. This carbonation cap also includes a barbtail on the underside so you can attach some beer line to act as a dip tube. This allows the carbonation cap to be used in several different ways including: 1. Carbonate 2. Cleaning your beer lines 3. Use it to counter pressure bottle fill PET bottles