This is a siphon with a cup on each end. The cups eliminate the need for suction before starting the transfer of liquids, you just have to fill the siphon horizontally and then hold it vertically.Printed without suports. Black ABS with 0.2 mm layers. The bottom part of the arch has a big overhang that might need supports, but I didn't need. It's possible to see in the pictures that the first layers of the overhang section were not perfect, but the didn't fall completely. It's essencial to have complete layers without holes. If the surface of the tube has holes the siphon won't work, because all the water will flow once you fill it.