SuperTrapp Stouts are 4" (10 cm) diameter slip-on mufflers and quench the thirst of riders longing for beautifully crafted chrome or black-bodied mufflers with a pleasant tone and unsurpassed performance gains. These non-tunable, massive 4" Slip-Ons allow riders to make a bold statement with their newly developed core. The streamlined, internal tapered, billet aluminum end cap with recessed fasteners comes pre-installed. The newly shaped inlets flow better into the OEM head pipe as well as SuperTrapp True Dual Head Pipes. The oval cut outs are a sign of the true craftsmanship that went into the design of these pipes. SuperTrapp Stout Slip-Ons provide a heavy, broad spread power curve right from idle with a 9.3 (16%) BHP and 10.5 (14%) ft.lbs torque gain over stock (measured on a stock 2010 FLH). Static tests according to the SAE J2828 standard these mufflers produce 95.6 dB(a) at 2,000 rpm, or 2.4 dB(a) over the stock mufflers on US domestic Touring models. SuperTrapp Stouts are sold in pairs for Touring models and single muffler for Street models.