Abstract: A funnel for use in filling containers with liquid and designed to prevent overflowing of the container during filling. The funnel has two air vents one of which is adapted to be closed during initial filling of the container while the other stays open to vent the container during this inital filling. When the container is nearly full, the liquid in it closes the second vent and this provides an indication in the funnel that filling is nearly completed. The first vent is then opened to allow filling of the container to be completed with a small amount of liquid remaining in, or added to, the funnel.