Society Motorcycles Oxygen sensor o2 Bung Adapters/Reducers for Harley Davidson Exhausts. Used to convert the older standard 18mm o2 sensor Bungs on pipes to The Newer 12mm Style O2 Sensors on Harley Davidson's Twin Cam & Sportster exhausts and more. For Oxygen Sensors with 12mm by 1.5mm thread pitch on pipes that uses 18mm by 1.5mm Thread pitch. Sold as a pair.
