Thunder Torque Insert suitable for 3" and larger single diameters. Features a high-temperature resistant powder coat finish. Stainless steel studs, 5/16" in diameter, are included. Comes with all necessary hardware. Enhances low and mid-range torque. Boosts exhaust gas velocity and inertial scavenging. Allows for adjustable sound volume and tone. Easy installation, bolts into the end of the slip-on muffler using the baffle bolt hole. Patented technology, proudly made in the USA.