I use this CO2 diffusor since some years in my 120cm tank. The water outlet on the top connects directly to a Juwel Eccoflow 500 pump head. In my tank, the diffusor and pump is installed behind a edge mounted hamburger mat filter. Outlet of the pump is feed through the filter mat with short piece of tube. In my configuration this tube also keeps pump and diffusor in place, as it sits quite tight in the filter mat.

CO2  inlet fits to a standard 6mm hose. 

Height of the diffusor is 150mm with a diameter of 54mm. The diffusor is split into two parts for easier printing. The bottom and top parts can be simply screwed together.

I have printed this with clear PETG. Unfortunately I didn't make a picture of the print.

Proper perpendicular mounting is important, otherwise the CO2 bubbles will leave the inside helix to early.