ITEM NAME:3" Catback Exhaust Header Down Pipe Manifold Collector Flange Gasket 2 Bolt Expanded Graphite & Steel 3" Catback Exhaust Header Down Pipe Manifold Flange Gasket 2 Bolt SPECIFICATIONS.Expanded Graphite & Steel 3" Catback Exhaust Header Down Pipe Manifold Flange Gasket 2 Bolt. Compatible With: fit for most import & export vehicles with 3" in/outlet 2-bolt exhaust flange only. Suitable for: cylinder head gasket, exhaust gasket and other internal combustion engine gaskets.