Kooks Custom Headers - 06-11 Charger/09-11 Challenger - 6.1L HEMI Stepped Exhaust Headers 6.1 Stainless Steel Stepped Headers With Required 02 Extension Harness. Comes with a Stamped Merge Collector and an Extra O2 Bung in the Driverside Collector. Tube 1 7/8 x 2 Coll 3”