This valve spring compressor tool is designed for Ford, Lincoln, and Mercury vehicles with many 1991-2004 2V 4.6L, 5.4L, and 6.8L Modular engines. It helps compress valve springs without removing the cylinder head, making it easier to service valve locks, spring seats, valve stem seals, rocker arms, roller followers, lash adjusters, and camshaft-related parts. Made of heavy duty carbon steel with a black oxide finish, the tool offers strong durability and corrosion resistance. The 3/8-inch square drive works with a ratchet or breaker bar for controlled operation in tight engine spaces. Not for Triton 5.4L 3V engines. Package includes 1 valve spring compressor tool.