This device allows you to carbonate a 1 or 2 liter PET soda bottle with the use of a home keg system. To use, just fill your soda bottle with beer, screw on the carbonator cap, attach a Co2 quick disconnect, and pressurize. If you want to make homemade soda water, carbonated fruit juice, or soda at home, there is no easier way to adapt your keg system to this function. A few of these, and you will never want to bottle again!