- Material and build quality: This valve spring tensioner tool is made of high quality steel with a smooth surface. The extension screws feature a steel ball to help keep the tool in place during use and prevent it from falling off. - Fitment: Professional quality valve spring compressor tool set suitable for use in cars, vans, small marine engines, and most motorcycle engines. - Versatility: Includes different size adapters, making this set one of the most versatile options on the market for removing and compressing springs on most cylinder heads. - Performance: Enables proper valve spring installation and makes it easier to squeeze the springs, supporting safer and more efficient work. - Use scenarios: - Car engine service: remove and compress valve springs during cylinder head work on typical car engines. - Motorcycle engine maintenance: service valve springs during top-end work on most motorcycle engines. - Small marine engine or van service: convenient for cylinder head work on small marine engines or vans, where spring removal and compression are required.