The classic Purple Hornie tubular design glasspack mufflers give sound and performance gains that are more than impressive - they're wild! The 16-gauge, 3.5 in. diameter steel shell encloses an interior spiral louver baffle design that increases exhaust velocity while decreasing backpressure, projecting the sound waves into a temperature fibermat material. Available in an 18 in. case length with 2.250 in. slip-fit or choose from three different styles of 3 in. three-hole direct-header-mount designs.