FEATURES: 19700 Valve Holder -- used when valve springs or valve stem seals are replaced, for use with a air compressor to help prevent the valve from falling into the combustion chamber. Fit for both 14mm and 18mm threads. HW0107 Valve Stem Seal Pliers -- Used to remove valve stern seals on the overhead camshaft engines, fits for most cars in the market. Quality -- All tools are made of high quality materials, they are sturdy and durable to provide years of trusted service. And all components are universal and versatile that fit for most car engines in the markets. .