Valve holder Fits 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 two-step fitting for both 14mm and 18mm threadsheavy duty 12″ flexible hose allows easy access to spark plug hole and air supplythread fitting to spark plug hole and other end to air supply. Skin-packed. Shipping wt. 4 oz.Lisle 19700 Click Here. Double your traffic. Get Vendio Gallery – Now FREE!