For the 4 or 6 Head Gravity Filler, the containers enter the gravity filler area in groups. Once the last container in the batch passes the mounted counting sensor, a pneumatic gate will engage an prevent other containers from interfering in the filling process. From this point, a product aligner engages the necks of each container, centering it under each fill nozzle which then the nozzles will lower into the opening of each container. Once securely seated on the bottle opening, the fill tubes will be opened. Once the air exits the container, product will flow in from the product tank. The fill level in each container is controlled by the position of the vent tube, making it a fill-to-level principle.