Vance & Hines 4 1/2 Hi-Output Slip-On Mufflers For Harley Touring Ride a high-horsepower Harley A bike tuned for high compression, large displacement, high-lift, or extended duration cams If so, these Vance & Hines Hi Output Slip-On mufflers are made for your motorcycle. By improving the volumetric efficiency of heavily modified or custom-built engines, these 4-1/2 pipes deliver maximum horsepower. Made to work on Harley-Davidson Touring bikes with M8 engines, these slip-ons feature CNC-machined end caps and also fit nicely with saddlebags and extended skirts. Features: Designed for modified high-horsepower engines Improve volumetric efficiency to increase power Compatible with dresser duals, power duals, and CVO drop skirt bags Deep, throaty tone Installing the Vance & Hines Fuelpak (or Fuelpak FP3 for 2007 models and later) is recommended for best performance on engines with electronic fuel injection For top performance, Vance & Hines head pipes and air cleaners are recommended