Aeroflow Performance features a range of different styles of high-quality weld onbungs and plugs to suit any M18 x 1.5mm oxygen sensors.  The oxygen sensor bung is a must have accessory for installing your wide-band oxygen sensor to your exhaust pipe. Especially If you are making custom headers, or justrequire a O2 Sensor in your system for data logging, engine management or test equipment. Works with Bosch LSU4.2, Bosch LSU4.9 and Aeroflow Performance (AF49-7501) wideband oxygen sensors. This range of bungs and plugs are available in three different materials ZincCoated Steel, CS1030 Steel and304 Stainless Steel to suit any application.