Vibrant STREETPOWER Oval Muffler (Polished 304SS, 2.5 In 2.25 Out) Vibrant Universal Streetpower 2.5in Stainless Steel Dual In Out Oval Vibrant Performance 1106 Streetpower 20" Steel Universal Muffler VIBRANT PERFORMANCE STREETPOWER Round Muffler, 4" inlet outlet (Center Vibrant Performance 1145 STREETPOWER Flat Black Oval Muffler Walmart.com. Don't be fooled by the classic, subtle style of the STREETPOWER range of Universal Performance Mufflers. Their "True Straight Through" internals ensures unrestricted exhaust flow for maximum power but they also feature dense, multi layer sound suppression materials inside each of these mufflers to help control exhaust tone and drone. All StreetPower Universal Mufflers feature PREMIUM 304 Stainless Steel construction, polished to a beautiful mirror finish. Catalog