Khrome Werks Hp-Plus Performance Baffle Inserts Unleash your beast with Khrome Werks performance inserts for 4.5 HP-Plus mufflers HP-Plus baffles emit a deep, mellow exhaust tone that is adjustable by simply changing an insert held into the baffle by two bolts Gives you control over your Growl Level Produces deep, rich tones with the perfect balance of performance and sound Change sound levels in minutes, not hours Specially designed for easy installation with basic hand tools (no hammers!) Features: For 4-1/2 HP-Plus mufflers Produces deep, rich tones with the perfect balance of performance and sound Change sound levels in minutes, not hours Gives you control over your Growl Level Sold as a pair