Abstract: There is disclosed an air knife for preventing transfer of liquid from one container to another. The air knife comprises an expansion chamber having a product inlet opening on to one container and a product outlet opening onto a second container. Around the circumference of the expansion chamber is positioned a distribution chamber. Air is input to the distribution chamber through an air inlet and a large bore inlet and passes around the whole of the annular distribution chamber. Several evenly-spaced small bore inlets allow ingress of air from the distribution chamber into the expansion chamber. The air, at a pressure greater than the fluid outside the product inlet and product outlet is forced out of the product inlet and product outlet thus forcing liquid adhering to an elongate product, such as a strip of components being electroplated, passing from the product inlet through the expansion chamber and out of product outlet, off the elongate product.