For Both 14mm and 18mm Spark Plug Threads. Commonly used when valve springs or valve stem seals are replaced. Air pressure helps prevent the valve from falling into the combustion chamber. Comes with...
TIME-SERT 10122 Metric Single Stainless Steel Insert M10x1.25 Length 14mm. This item ships from the manufacturer with a minimum order quantity of 10.
Generic image above. TIME-SERT replacement...