The Ace Race Parts brand of metric Oxygen (O2) Sensor Bungs are precision machined using solid 304 Stainless Steel bar stock and work with all standard O2 Sensors that use a M18 x 1.5 thread. This specific O2 sensor bung fitting features a 45° Angle cut design. Our O2 sensor bungs and bung plugs are a high quality 304 stainless steel option for custom exhausts, downpipes, and OEM repair fabrication projects.