Especially during long trips to camping or stays in the garden you should always have this emergency pump at hand: Insert the end towards which the arrow on the pumping bellows points into the container into which you wish to fill the liquid. Hold the bellows so that the arrow points upwards and start pumping. As soon as you are sure that the liquid flows by itself, the arrow can point down again. A non-return valve ensures that the liquid flows into the container without further pumping as long as the container is lower than the level of the liquid to be sucked off.