This Stainless Steel adapter allows you to use a full size 18mm thread O2 Sensor in a 12mm Original Equipment bung. Most Import Motorcycles, ATV's etc. come with a 12mm O2 sensor. This adapter allows you to use one of Innovate's Data loggers or Gauges without the need of welding in a new Bung. This Adapter allows mounting the O2 Sensor at a 45-degree angle. The nut allows you to point the Adapter in any direction for the greatest amount of clearance.