Stainless Steel: Made of stainless steel, super rigid, sturdy and not easy to erode. Resistant to all weather conditions. Curved: The curved design ensures a perfect weld on your exhaust system. Just drill a hole and weld it. Suitable for most O2 sensors on the market. CNC Technology: x 1.5 threads cut by the latest generation of CNC technology, high precision can be absolutely ensured. Don't worry about the nut specifications. Fitment: Universal Part x 1.5 Oxygen Sensor Nut Weld Bung Material: Stainless Steel Color: Silver Package Contents: 4 x Oxygen Sensor Nut Weld Bung Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.