The 20530 is a 10mm thread adapter. Adapts to M14X1.25-6H Threads.??í
The Lisle 20530 Spark Plug Adapter is a replacement adapter designed for 10mm spark plugs and is compatible with the Lisle Compression Tester LST 20250. It comes with an O-ring for a secure fit and accurate compression readings.??íOne reviewer says this fitting works perfectly when attached and provides plenty of threads to complete a test.
