The T-4® offers performance without the flash. Constructed of lightweight brushed aluminum and stainless steel, this muffler is built tough. The innovative design provides huge horsepower increases and faster; stronger response during hard acceleration. Like the Ti-4®, the T-4® will give the racer the ability to tune his bikes performance with a selection of end caps that change the powerband of the bike around the needs of the rider. Quickly changed, the standard end cap, the optional smaller and bigger end caps offer tremendous performance gains. Also, can be used with the OEM stock or a Pro Circuit standard head pipe. When it comes to racing, the T-4® is one of the most sought after four-stroke performance mufflers on the market today.