A poor man’s Sealand alternative

[mickmanor]

I am not a plumber, so I am asking for a description for the white pvc 1-1/2" fitting
that goes on the tank for the air vent connection. I have searched, but nothing found.

Again, great job, kind of like putting the icing on the Trailmanor cake!

I am accumulating parts, and so far, I have the tank and vent. Thank goodness for that.