Vance & Hines engineers developed a sophisticated sound-canceling chamber within each muffler that provides a perfectly measured increase of the exhaust note & produces a usable increase in torque & horsepower. GL Monsters are oversized slip-ons that feature an angular design finished with massive 6-1/4” wide machined billet end caps that elegantly accent the GoldWing’s bold stance. The full-length blue proof heat shields cover both the exterior & drivetrain-side components. The mellow exhaust note & the distinctive looks GL riders have longed in a system designed as well as the GL itself.