Exhaust Pipe Reducer Adapter Sensor Spacer Reducer Adapter Oxygen Sensor Reducer Adapter O2 Sensor Reducer Adapter NPT To BSPT Reducer Adapter Oxygen Sensor Reducer Adapter With Gasket AN4 Female AN3 Male Adapter Reducer 1 8NPT To BSPT Reducer Adapter Female Male Pipe Adapter Coolant Pipe Adapter Coolant