Weld On O2 Sensor Bung M18 x 1.5 Stainless Steel Saddle O2 Oxygen Sensor Weld In Bung & Plug M18 x 1.5 Stainless Steel Adapt Exhaust 02 Lambda Boss Weld On Bung T304 Stainless Steel Sensor 1.5mm x Stainless Steel 18mm x 1.5 Weld In 02 Bung Female Fitting Oxygen Sensor 2 Sets O2 OXYGEN SENSOR M18 X 1.5 BUNG & PLUG WIDEBAND WELD ON IN NUT. Vibrant Performance saddle style weld on oxygen sensor bung is made of 304 Stainless Steel for the utmost in optimum corrosion resistance. Vibrant Performance saddle style weld on oxygen sensor bungs feature a radius design which allows for a cleaner weld to tubing.