●Main Application The notched nut with oxygen sensor curve is good for precision welding of your round pipes. ●Size The thread pitch is 18mm x 1.5mm. This is the typical thread pitch for oxygen sensors of 99% on the market. Stable performance and long service life. ●DURABLE CURVED NUT - High quality welded FAB-PROS plug with round tube notch (also called "coped") at the bottom. Made of high quality stainless steel for stability. ●Package includes: 2 pieces curve notched nut. Easy to install, direct replacement for old or defective. Easy installation and high availability. ●100% Guarantee:Our warranty period is 12 months. If you encounter any problems during your use, you can contact our customer service. It will offer you a solution in time.