06-07 SUZUKI GSXR600: Two Brothers M-2 Slip-On Series Exhaust (Carbon Fiber) The original TBR System. Adding this Two Brothers Racing high-performance exhaust system will help you gain additional horsepower while lowering the overall weight of your bike. Made from the finest materials, this exhaust system features a Teflon-coated magnesium endcap, gold CNC-machined inlets and outlets, and stainless steel hardware for a durable, performance driven exhaust system. All M-Series exhaust systems feature the TBR spiral-wound perforated core which gives each exhaust system that distinct, deep, Two Brothers exhaust note. Teflon-coated magnesium end-cap.