2008-Present Toyota Sequoia 4.6L & 5.7L Bolt-On Catback. Available in stainless steel and aluminum. Easy installation. Painted in a high heat resistant black powder coated heat. Helmholtz is optional but strongly encouraged as the eliminate drone at cruise speeds. The device is BUILT IN. It cannot be taken out after it is built. The Helmholtz Resonator does not effect performance. Its sole purpose is to eliminate drone inside the cabin for a more enjoyable ride.