Material:This part is genuine stainless steel, with excellent material, smooth surface and longer service life.
Expansion Plug (part number 3900965) is a small, round metal plug used to seal a hole in the engine block or cylinder head.It is made of stainless steel, creating a secure and leak-free seal. Expansion plugs are commonly used during the manufacturing process of an engine block or cylinder head, but can also be used for repairs. They are essential for maintaining proper pressure within the cooling system and preventing coolant leaks that can lead to engine damage.