Shower base -- this doesn't look right

[Reach4]

there is a reducing donut that I found at Menards (https://www.menards.com/main/plumbi...8181399646.htm?tid=8937141462024246486&ipos=2) that is a snug fit in the 3" inlet,

That is only for use with the Fernco "Qwik" stuff.
https://www.fernco.com/products/flexible-couplings/qwik-tees-ells
I don't think that would meet codes.

 

[Sean35]

I figured as much. It was just one of those things where I started grabbing anything I thought I might have use for, and it was like "well, this piece fits in that piece", so in the cart it went.

 

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[Sean35]

Somehow I managed to walk past it 500 times in the past week without noticing, but the lav (or, former lav, as I gave it away last week) has an s-trap, so I have to address that now too. That pipe wasn't attached to anything either, there was just a rubber gasket holding it in place.

Also, would the old layout of the shower drain have been considered an s-trap?