The answer is rubber-coated metal. Head gaskets are used to <span>compress the engine block and the cylinder head. Another use is that it seals the internal combustion process and prevent the oil and coolant from mixing together as they travel from the engine block to the cylinder head.</span>
A good advancement would be a portable radio. They have made life easier for people who are walking/hiking and are looking for something such as the weather for the night or the score for a sports game.
