Supertrapp 725-71235 Internal Disc Series Slip-On Exhaust The SuperLight Stainless Series Slip-Ons for Buell models utilize our patented Tunable Disc Technology This system is available for X1 Lightning, M2 Cyclone, S-3 / Thunderbolt and S-1 Thunderbolt White Lightning This system is lightweight It produces almost 4% more horsepower than any other system tested, and it does it without any other modifications Corrosion-free Stainless Steel with a low-slung look