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" 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" case length with 2.250" slip-fit or choose from three different styles of 3" three-hole direct-header-mount designs.