Upgrade or maintain your EMPI exhaust system with these replacement muffler inserts, designed specifically for use with EMPI P/N 56-3709-0 and 57-3759-0 exhaust systems. Built to the same high standards as your original equipment, these inserts are sold individually and provide a perfect fit to keep your exhaust performing optimally. Whether you're maintaining your system or boosting performance, these replacement inserts are essential for keeping your exhaust system in top condition.