Features and Benefits: * 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 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. Skin-packed. Shipping wt. 4 oz.