Flush and fill your bottles with ease. The valve has three positions: off, beer, and gas. Insert filler into the bottle in the off position, switch to gas to flush the bottle with CO2, and then switch to beer to fill your bottle. You can control the speed of your flow with the adjustable pressure relief. This filler is designed for use with 12 oz. bottles but can be used with larger formats by attaching a small piece of 1/4" tubing to the filler.