CNC Machined from 316 Stainless Steel means these exhaust flange kits are virtually indestructible! 316 Stainless is one of the most corrosion resistant materials on the planet. No more ugly, rusted out exhaust clamps when using these. Original Equipment flanges can sometimes bend or distort which can lead to exhaust leaks. These Stainless Steel Exhaust Clamps are machined out of high quality material, so they will not bend or distort even under high pressure. Available in three different ARP hardware choices: 12pt. polished, Black Oxide Hex, and Polished Hex Nuts. Each Kit comes with two flanges, two exhaust circlips, and four exhaust nuts.