Description : Super good 304 stainless steel . Durable , never fade . Withstands high exhaust temperature . easy - to - screw threads or can also be welded . Perfect to replace old or broken nut . Specification : Material : 304 stainless steel Plug Outer Diameter : Approx 25mm Plug Length : Approx 16mm Bung Outer Diameter : Approx 25mm Bung Length : Approx 13mm Thread : M18 * 1 . 5mm Package Includes : 1 Piece O2 Nut (5 Pack) Note : Please allow 0 . 5 - 1 inch difference due to manual measurement .( 1 inch = 2 . 54cm ) Please check the size measurement and the picture carefully before making payment . Due to the difference between different monitors , the picture may not reflect the actual color of the item . Please understand , Thank you .