What is the part between the air conditioner and the roof of a 3124KB (and it looks like other models with roof mounted AC) called? I put some arrows at what I'm talking about in this photo:
I noticed there seems to be a very precise caulk/seal around the edge of this on the part that attaches to the roof. I also noticed there is some additional caulk that someone added at the front side of this and I'm wondering if I'm redoing all the other caulk, should I do anything there?