Cobra 4.5 RPT Slip-On Mufflers For Harley Touring The 4.5 RPT 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. Features: Features satin black laser-cut steel straps that tightly encircle the mufflers with built-in mounting straps The frequency and location of the perforation patterns in the cores creates significant sound scattering in the mid frequencies, which helps to enhance the low frequency tones 3 cores for superior performance Acoustical engineering developments allow an incredibly deep sound 4.5 bodies taper to 4 round at the front 4.5 machined aluminum thin line black tips are held in place with seven stainless steel, 12-point bolts