Kweiny Engine Air Valve Holder and Cylinder Leakage Testing Assistant Tool Fit with M12 or M14 Thread

About The Item: Main Usage 1: Pressurizes The Cylinder To Help Hold Valves Closed With Compressed Air. So The Oil Seal Of The Valve Can Be Replaced Without Dismantling; Main Usage 2: When The Cylinder Is In The Compression Stroke. If The Air Tightness Of The Engine Is Not Good Enough, You Can Hear The Continuous Leakage Of Air. Diagnosis Of Damaged Parts By Listening To The Leak Position; Compatibility: Suitable For The Gasoline Engine With M14 Or M12 Spark Plug. The Joint Of This Tool Must Be .