Vance & Hines Classic Slip-On Mufflers - Turn Down without Billet End Caps 16761 High-volume, 4in diameter slip-ons provide substantial power increases, improved fuel economy and crisper throttle response All Classics provide the perfect sound from your Big Twin; not too loud, definitely not too quiet, and the baffles are removable Systems include all necessary hardware and mounting instructions for a hassle-free, perfect fit every time Optional quiet insert, requires baffle modifications, available separately Made in the U.S.A.