This stainless steel ball lock cap features soda bottle threads, allowing you to convert a 1 or 2 liter soda bottle into a convenient travel growler. The ball lock is compatible with both gas and beverage disconnects, so you can charge the PET bottle before you leave the house and dispense on the go. Attach 3/16" or 1/4" ID tubing to the barb to serve as your dip tube and you're all set!