what kind of muffler is this?

The shell resembles Flowmaster, but I can't tell if/where the insides are welded to figure out whether it's using baffles or perforated tubes and some sound-deadening material. It could be a Flowtech Terminator or something of the sort.

nope not a flowtech, flowtechs dont have a marked inlet side and they are also reversible some kind of flowmaster knockof is my gues