In my basement machine shop, I installed a central vacuum cleaner with a Kärcher WD3 P shop vac, a cyclone separator with 30 l barrel and 50mm sewage pipes for distribution. To attach the Kärcher's suction pipe to the sewage pipes, I needed some socket matching the Kärcher plug at the suction hose. Here it is.

The socket consists of two parts: The socket itself and a lid that closes the opening when the suction hose is not plugged in. They are printed best top-down and with tree support (Cura) for the socket. They both have a small notch for inserting a small screwdriver for separating the part from the print bed.