Weld-in O2 sensor bung lets you incorporate O2 sensors into any exhaust system 18 mm x 1.5pO2 sensor bung plug works with any O2 sensor port 18 mm x 1.5pAluminum bung plug washer works with any 18 mm O2 sensor bung plug Product NameBungThread Diameter18 mmThread Pitch1,5 mmThread Pitch Metric1.5 mmTypeO2 SensorUnitsKitVendor part numberBG001813