GM Genuine Parts Spark Plug Boots are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These boots fit at the end of spark plugs and act as insulators to help protect from moisture and contaminants and helps promote long spark plug life. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).