Big Gun Evo R Head Pipe Honda Trx400Ex / Trx400X The EVO R Series stainless steel head pipe not only offers a significant reduction in weight but also enhances performance noticeably. It produces a superior sound compared to the standard stock, making it an ideal upgrade for better acoustics and efficiency. Features: Precision-bent TIG welded 304 stainless steel head pipe Larger diameter than stock head pipe Lighter than stock head pipe Increased horsepower and torque gains Handmade in the USA Note: Images are for reference only. Not compatible with stock muffler.