Vibrant 2 1 SS Merge Collectors (1 1 2in Inlet Slipover ID 1 3 4in 2 1 SS Exhaust Merge Collector Dual 2" ID Inlet Single 2.5" OD Outlet Vibrant Performance 10352 VIB10352 2 1 S.S. MERGE COLLECTORS (1.75IN Performance Slip On Merge Collectors: 2 1 4" 4 into 1 Vibrant Merge Collectors 21 SS 2in Outlet OD Sold Individually eBay Performance Slip On Merge Collectors: 1 5 8" 2 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.