A pipe for carrying a fluid, having a longitudinal axis and defining a radial aperture for release of a jet of fluid having a radial direction component \u03b1, the aperture having an aspect ratio greater than 2 and arranged with its elongate axis within 30 degrees of the longitudinal axis and having area greater than 0. A conveyor belt holds coins together with the passage surface to convey coins along the guide member. Side inlets are defined between the cover plate and the air guiding member. Docking stations are also described that can communicate with one another to extend the feature sets of each.