Hedman Stainless Steel Headers are constructed from 304 stainless steel instead of less expensive 409. 304 stainless steel has more Chromium & Nickel than 409, which provides superior heat and corrosion resistance. Additionally, 304 will not rust or flake like 409 stainless steel. This means Hedman Stainless Steel Headers will retain a cleaner look and endure extreme temperatures better than headers made of 409 stainless steel. Hedman Stainless Steel Headers use sturdy laser cut 3/8" flanges, and all primary tubes have smooth-flowing mandrel bends. They're also available with Hedman's HTC Ceramic-Metallic coating for a shiny finish and lower underhood temperatures.