This is a vortex amplifier, a fluidic element for amplifying a fluidic signal. The supply flow(flow going straight into the circle) can be modulated by weaker control flow(flow going tangent to the circle) by the control flow inducing a vortex in the chamber. This vortex increase the resistance to flow, thus amplifying the signal from the control flow. In short, apply flow to the control flow port and there will be less flow coming out of the output port.Print both Vortex_amplifier.stl and Vortex_Plate.stl and bolt together tightly with M5 screws.If you're having trouble with leakage, cut a piece of double stick tape to shape and put it between the plates.Or if you're feeling more adventurous, print it as one piece by printing Vortex_amp_assem.stl.Connect to other fluidic elements using 5/16" tubing.Now if you want to do something really cool, run this device with water and don't put anything on the output port(center port), you should now have a jet, now apply pressure to the control flow port, the jet at the output port should turn CONICAL! It should look something like this: http://fritopia.info/page1/topic_pages/stuff_I_made/fluidics/vortex_diode/vortex_side.JPG http://fritopia.info/page1/topic_pages/stuff_I_made/fluidics/vortex_diode/vortex_front.JPG http://fritopia.info/page1/topic_pages/stuff_I_made/fluidics/vortex_diode/vortex_rear.JPGNow hook up a fluidic oscillator to your control port and you should be able to make a small one of these: http://www.tippettsfountains.com/jetspray.php