For Acura Integra GS/LS/RS Stainless Steel 4-1 Header/Exhaust Tubular Manifold Made of High Quality T304 Stainless Steel Material; 4-1 Design TIG Welded CNC Machine Flange; Direct Bolt-On Installation, Requires NO Modification Increase High Flow Air, Instantly Gain 10 -15 Hp. / Tq. 1.75" Inlet / 2" Outlet / Metal Gasket Included Professional Installation is Highly Recommended; Installation Instruction is NOT Included