For BMW 3-Series E36 6-2 Stainless Steel Exhaust Header - I6 engine Made of High Quality T304 Stainless Steel for Strength & Durability TIG Welded CNC Machine Flange for Percision & Fitment Offers the Best Flow Characteristics for the Engine at High Engine Speeds Increase High Flow Air, Instantly Gain 10 -15 Hp. / Tq. 1.75" Inlet / 1.75" Outlet / O2 Sensor Bung Insertion & Gasket Included