Specifically designed to replace the stock 2-1 muffler of the Switchback and Dyna Low Rider. The large 4" diameter muffler body with a maintenance free baffle provides you with the perfect blend between power and sound. Note: Compatible with OEM header pipes. Note: Will not fit 2017 model year Dyna HDI (H-D International / EU models). These come with thinner ending header pipes and US slip-on mufflers will therefore not fit.