Is AAV fitting too big? Why do all mine look like this?

[Johndoejohndoes]

I was taking a look at the AAV on my sinks and the fitting looks too big on the piece connecting the AAV.

I looked underneath and see this…not sure if this is normal and sealed properly?

 

[Jeff H Young]

Ive never put one in but it could be that it fits multiple size pipe up to 3 inch. Why did the trap arm get modified like that and why the AAV ?

 

[Sponsor]

 

[Gagecalman]

You can use that for 1-1/2" and 2" pvc pipe so that is the socket for 2". It's fine.