Ideal for connecting headers with a 3-bolt 3.0 inch flange to your 2-1/2 inch exhaust system. Features: Adapts 3.0" 3-Bolt Header Flange to 2-1/2" Exhaust Complete Collector/Reducer Kit w/Reducers, Flanges, Gaskets & Hardware Heavy Gauge Collector Ring Grade 5 Bolts w/ Lock Nuts Retail Packaging About Mr. Gasket