Optional Stainless Steel Link Pipe With Resonator For Mounting With The Muffler And Header Set From The Evolution Line S-H10E3-APLT Or Racing Line S-H10R9-APLT. It Lowers The Noise Levels For Use On Racetracks Where Lower Noise Levels Are Required.Static Noise Level With Noise Insert: 97,1 DB@5500 RpmStatic Noise Level Without Noise Insert: 100, DB@5500 RpmFor Perfect Performance, Throttle Response And Durability, ECU Remapping Is Recommended.THIS PRODUCT DOES NOT MEET EMISSION COMPLIANCE REQUIREMENTS FOR STREET OR HIGHWAY USE.