What's this connection piece

[sgdzw]

Hello experts! Question from a novice DIY home owner I'm thinking of replacing my bathroom sink, including the P-trap. I've watched Youtube videos and know the rough steps. However, I don't recognize the extra metal piece connecting the waste arm and the pipe out of the wall. Took pictures of the overview and a close view on the piece I don't recognize. Do I need to worry about this piece? My guess is I can just keep it and replace everything up to the waste arm (sink, tail piece, p-trap, waste arm), but just wanted to make sure... Thanks!

 

[TomFOhio]

Yes, take that chrome slip nut loose and pull that pipe out. Run new plastic drain pipe from there. You got the right idea.

 

[sgdzw]

That's great to know. Thank you, TomFOhio!