Pneumatic Valve Holding Tool

For Both 14mm and 18mm Spark Plug Threads. If you're leaving the heads on your engine while doing a cam and/or spring swap, keep things simple with a pneumatic valve holding tool. Thread this into the cylinder working on, pressurize it with your air compressor, and work away knowing that your valves will never leave you, unlike your ex-wife. 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 two-step fitting for both 14mm and 18mm threads. Heavy duty 12" flexible hose allows easy access to spark plug hole and air supply. Thread fitting to spark plug hole and other end to air supply.