What you get: 1 package includes 4 packs of M18 x 1.5 oxygen sensor fitting bungs, applicable to most car's O2 sensor threaded socket or tool and can be screwed into upstream and downstream O2 sensor and car exhaust

Product function: having the "oxygen sensor adapter" backing it out of the way of the exhaust flow, the oxygen sensor restrictor fitting is beneficial in tuning your air or fuel ratio by hooking up a potentiometer to your oxygen sensor or MAP sensor

Durable and well polished: the oxygen sensor restrictor fitting is made of iron plated metal, durable to use and the appearance of all oxidizers is well polished, avoiding cracking and excessive heat expansion

Size info.: these oxygen sensors fitting bugs are M15 x 1.5 sized, universal 18 mm threaded socket, suitable for most modern vehicle cars, fit for custom exhaust, headers, down pipes or for adding a extra 02 sensor for use with a wideband

Easy installation: suitable for most modern vehicle cars and can be screwed into upstream easily, easy to install, just bolt them on and you are ready to go; Please make sure you have enough room to install these