American Standard Cadet model 3275 - Plastic piece inside of pipe

Yes, there is a non-replaceable plastic restrictor device screwed into the tub spout outlet of the faucet body. It's purpose is to force the flow down to the spout for when the spout diverter is not closed. It keep water from rcoming out of the shower head when the tub spout is also discharging.

This is all fine and dandy where the water supply is clean without sediment. A co-worker of mine had one of these and old galvanized piping. After 3 years, it clogged up. She got a 'deal' from a handyman plumber to replace with an identical faucet. She will have the problem again. If she had spent the money to fix it right, she would have had a single handle mixing valve put in. If it clogs, you can just pull the cartidge from the body, clean it and put it back in. Now she will have to cut into the wall again, get the plumber to replace the 2 handled unit and patch the wall again.

Or, she could have the plumber drill out/remove the restrictor but then she might get water out of both outlets at the same time....."pay me know or pay me later"....repalcing the mixing valve with a scald prevention single handle valve (with remodel plate) is the BEST long term solution.

Fred Grable
Chicago
(Engineer and Ex-Master Plumber)

This is supposed to be removed. If I thinking correctly, this is a large black plug that is used as a dummy so you can pressure test your connections without seating your valve. Your install manual should refer to this piece.