This universal resonator is designed to add a weld-in (or clamp-in for existing systems with V-Band clamps) resonator to some of our exhaust systems, or any 3 IN exhaust application (there is also a universal resonator delete pipe for those wanting to remove a resonator in an existing exhaust system see Part #49M100005). They feature weld-in V-Band flanges for a tight, leak-free fitment