For Infiniti G35 Performance Stainless Steel Exhaust Header Kit (Downpipe Included) Precision machined steel flanges that provide a tight seal at the head and allows a high flow rate through the primary tubes Made From High Quality T304 Stainless Steel For Strength & Durability Constructed With TIG Welded CNC Machine Flange For Percision & Fitment Comes With Downpipes Inlet/ Outlet: 2.25"/ 2.25"