Peace be upon you. I have 2 Sierra cat-back exhaust systems from model years 2019 to 2026. One is Borla and the other is Edlebrock. I have a video that clarifies everything. Whoever wants to see it, DM me. Peace be upon you. Good evening. These are items for Sierra 2019 and above to 2026. The headers are 2 inches. The Y-pipe is 3.5 inches. The rest of the headers are 3.5 inches. The first muffler is Borla, it's clean and has a silencing muffler as shown in the picture. The second muffler is Edlebrock, it's a catalytic converter with packing to reduce carbon smell. Contact me via DM There is also a video showing everything in detail for serious buyers.