Khrome Werks 3" HP-Plus® Slip-On Mufflers - Tapered - Chrome - XL421213438 Product Description Patented steel construction baffle now features more high temperature fiberglass packing, provides significant gains in horsepower and torque and exhibits a distinctive, throaty sound Use all factory mounting hardware OEM heat shields may be retained U. S. patent 5,173,576 Made in the U. S. A. ECM units on fuel injected models need to be recalibrated if used with free flowing air cleaners and or modified engines. Muffler