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 96, 103, and 110 cubic inch engines, these slip-ons feature CNC-machined end caps and also fit nicely with saddlebags and extended skirts.; Designed for modified high-horsepower engines Improve volumetric efficiency to increase power Work with 96, 103, and 110 cubic inch engines Compatible with dresser duals, power duals, and CVO drop skirt bags 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 Optional quiet inserts 442-831 sold separately