It can be unpleasant when the threads in the cylinder head are simply stripped from the spark plugs when tightening them. And since on most cars it is made of soft aluminum - it does not happen so rare. In such cases, a kit for restoring the threads of spark plugs will come in handy. The kit comes with a reamer and 4 bushings with threads of different lengths: 9mm, 11mm, 16mm, 20mm.