uh.......DC Sport Headers are 4-2-1, so the part u talked about must be 2-1. I don't know how to put this since I don't know the exact term, but let me try my best ok?

you know the outlet of the Engine is 4 holes, so the VISIBLE part of the header you see (when u openned the hood)is

1st part - 4 airflow outlet combining into 2.

Then there're a 2nd part that connect to the end of the first part and combined 2 into 1 pipe air flow.

Then its end will connect to the front part and that FRONT part connects to the Catalytic Converter.

It's better this way because the 4-2-1 setup allows more air flow into you exhaust system, yet give your car a lil more power. Unlike other cheapo headers, it's only 1 piece and converted from 4 outlet into 1, less airflow, HOT engine, not that good.

Hope this help.

and I think that it does not matter whether it's stainless or ceramic, DC sport made 4-2-1 headers for 5th Gen HA.