It's the Thunder cat-back (same as my header).
Pieces are beatifully made. Diameter is same as stock, about 2", so I'm not going to recommend it for anyone going FI or planning a major build. But for the rest of us whose plans don't extend realistically beyond getting to 125-130 whp, it's more than enough.
There are going to be two muffler choices for the sedans, the one above and an Apexi N1 style (comes with a silencer). I'll have pics for that on Monday. The P5 will only have the above one available in a shortened to fit version.
You'll also be able buy the axle-back and resonator/S-pipe separately so for anyone who already has the MazdaSpeed or other axle-back already, you'll be able to complete your cat-back without having to buy another full set.