O2 WELD-IN SENSOR BUNGS. 12 x 1.25mm. Straight. Used to install O2 sensors in exhaust systems. Weld-in style. Available in 12 x 1.25mm or 18 x 1.5mm styles. Available in a standard straight style, or machined at a 45° angle. Sold in pairs. Made in the U.S.A. - Part Number - 1861-0561