The Power Spout screws directly onto the pull-out spouts found on VP Racing Fuels 5 Gallon Pails making the transfer of liquids much easier. The vent tube allows air to flow into the bottom of the container releasing the internal pressure resulting in a smooth and quick pour. NOTE: VP Power Spouts are designed to ONLY fit VP Racing Fuels 5 Gallon Tin Pails, not Plastic 5 Gallon Motorsport or Sportsman Containers.