For me, space was critical, the fitting was above the waterline, it was not really pressurized and this was all I could find with those dimensions. I set up a 12v utility pump with a momentary switch to suck the meltwater out of the icebox and dump it down the galley drain.

I was thinking of doing something similar on the IP, that icebox also goes to the bilge along with many other things. I would rather plumb it to go over the side.