I've remixed the T-Rex shower head to fit on an Aussie shower thread (½" bsp thread).
Print with the flat side down, no supports. I used PLA, 3 shells. You don't need much infil. I used 20% gyroid, with 3 steps (in Cura).
The shower head part uses bridging (and voodoo magic) to print without the supports.
trex-shower-aussie.stl | 16.4MB |