This thing is meant to connect an Intex pool inlet (3th image) to a standard garden hose click connector (4th image). One of the things you can do with it is connect a pool vacuum cleaner (one that needs water to go in it) to the inlet. So you don't have to use tap water while vacuming. I haven't printed it yet so it is not tested. I will update as soon as I tried it. I used the garden hose coupler by Lampmaker. I used threads.scad by Dan Kirshner.Remember you have to put a rubber ring around the top of the garden hose connector. You can buy it in a DIY centre.