Vibrant 2 1 SS Merge Collectors (2 1 4in Inlet Slipover ID 3in Outlet 2 3 8in x 4 1 2in Merge Collector RV Parts Express Specialty RV Vibrant Performance 10356 VIB10356 2 1 S.S. MERGE COLLECTORS (2.25IN Vibrant 10332 3 1 Merge Collector, 1.625 In ID, 2.5 In Outlet Vibrant Merge Collectors 21 SS 2in Outlet OD Sold Individually eBay Performance Slip On Merge Collectors: 2" 4 into 1. Vibrant Performance has developed a comprehensive, high quality and Affordably priced range of 304 Stainless Steel Merge Collectors to help our customers free up maximum horsepower from their exhaust setup. For many years, merge collectors were almost exclusively used by top professional race teams. However, this proven technology is now commonly used at all levels of professional racing (where rules permit) and now many fabricators are incorporating merge collectors into street header applications.