Pro Circuit 4H01080 T-4 S/A Complete Exhaust System Full spark arrested exhaust for your four stroke dirt bike and ATV. Round aluminum silencer body with aluminum end cap and nickel plated connector. Comes with stainless header and mid pipe. Quiet core insert available. HP gains throughout range. Designed for easy disassembly and repacking. Removable USFS approved spark arrestor. Meets AMA sound restrictions.