Vance & Hines Twin Slash Slip-On Mufflers - Oval Monsters 5 1/2in 16765 This series of slip-on mufflers for touring models incorporates THE best of Vance & Hines and redefines performance, looks and price with a distinctive style and unmistakable sound that is only available here Ovals are available in either a 4 1/2in version with an all-mechanical straight through louvered baffle for generating power gains with an aggressive exhaust note or 5 1/2in Monster version which has won over touring riders across the country with their power gains and perfect sound 2-into-1 version was designed specifically to work with the new 2-into-1s on 10 Road Glide and Street Glide; features a large 4-inch, stepped to 4 1/2in, muffler body that uses an all new maintenance-free baffle that also minimizes heat discoloration and provides the perfect blend of sound and power gains All feature the new signature Twin Slash end treatment Made in the U.S.A.