M4 Exhaust manufacturers high-quality exhaust systems for all popular sportbikes and dirt bikes. M4 Exhaust systems are precision made for Suzuki, Yamaha, Honda, Kawasaki and Triumph. M4 Exhausts also offers GP-Syle, High sport, Race and standard exhaust systems in both Full and slip-ons exhausts. M4 Exhausts are carefully hand crafted for optimum performance using the latest high-tech methods of materials. M4 Full Exhaust Systems are the ultimate in performance tuned stainless, including all Mounting hardware. M4 Bolt-Ons Exhaust and M4 Slip-ons Exhaust utilize the Stock Headers Assemble. They Bolt-on or Slip-on replacing the Stock Restricted Muffler, resulting in a better sound and an increase in power.