The S1R Black Series exhaust is a state-of-the-art product from Two Brothers Racing The system features a natural finished Aluminum outlet and stamped spring-mounted inlet for ultimate durability The S1R Black Series exhaust from Two Brothers Racing showcases a race design while increasing all-around performance Features: Teflon coated magnesium end-cap Stamped spring-fit inlet Aluminum CNC Machined outlet Rubber-lined styled mount Spiral-wound perforated core Accepts P-Series sound reduction tips Note: For closed course competition use only. Not intended for street use