These headers are designed to improve exhaust flow and enhance engine sound. The ceramic coating aids in reducing under-hood temperatures. Headers are used so they aren't chrome anymore but are still perfectly functional. They feature 1-5/8 inch CNC-mandrel bent tubing, 3/8 inch thick flanges, and a durable ceramic coating. These 50-state legal header are a direct easy bolt-on. What you see is what you get.