The 4" Race-Pro Slip-On Mufflers offer advanced acoustical technology for the deep rumble riders crave. The muffler system is beautifully chromed, but what sets the mufflers apart is the unique black steel strap that is secured tightly around the muffler bodies. Race-Pro Slip-On mufflers consist of 3 inch baffle cores that are conjoined with Cobra's proprietary sound tuning with materials with specific acoustical dampening and thermal insulation properties.; These novel 4" muffler bodies feature advanced acoustical tuning technologies for a deep rumbling sounds The 4" round muffler front expands just after the steel clam shell clamp to 4-1/2" diameter The gloss black finish on the aluminum tip is matched with the gloss black finish on the laser-cut steel strap that tightly encircles the muffler and has built-in mounting points With its unique strap the Race Pro looks like a radical departure from the norm, when in fact, the Race Pro mounts the same way as nearly every slip-on muffler from Cobra The strap clamps tightly around the muffler and bolts to the bike's hanger mounts located beneath the saddlebags PEM fasteners in the wrap make mounting a simple task of threading in a bolt from the upper bracket into the Cobra strap Like all Cobra exhausts the Race Pro slip-on mufflers are made in the U.S. and come with a limited lifetime warranty that even covers discoloration