What is this bathtub part called

[Nukeman7]

The missing plate was there when we moved into the house in 1974. It's never been "upgraded" unless done before then which I doubt. The only access to that area behind the tub is by tearing out a wall. Something I'm not going to do.

Never had any smells out of it either.

If you don't have the trip-lever type of drain stopper, it would not need or have the weighted bob stopper. How do you stop up the drain to fill the tub for a bath? It must either have the pop-up/pull up+twist stopper or a rubber stopper unless you use a flat rubber disc drain cover.

The P-trap has been required by national plumbing code to prevent sewer gas infiltration way before the '50s.

 

[Chris142]

If you don't have the trip-lever type of drain stopper, it would not need or have the weighted bob stopper. How do you stop up the drain to fill the tub for a bath?

Rubber plug

 

[doitmyself]

Rubber plug

There's more elegant replacement stoppers. Some screw in, others like the one below simply push in:

 

[Chris142]

There's more eloquent replacement stoppers. Some screw in, others like the one below simply push in:
View attachment 250816

Elegant? Ha! You don't know me at all lol

 

[doitmyself]

Elegant? Ha! You don't know me at all lol

We used a rubber stopper for 12 years when our lever model broke (my alter ego lazy side). Just last year I had to replace the entire drain/trap assembly and learned about these fancy pop up style ones. I'm livin' high on the hog now!

 

[wpod]

Ya Its pulled away from the tub. I have to add some sort of caulk

They make gaskets for that and the drain cover shouldn't cost you that much.