ACDelco GM Original Equipment Spark Plug Boots fit at the end of spark plugs and act as insulators to help protect from moisture and contaminants and promote long spark plug life, and are GM-recommended replacements for your vehicle’s original components. These original equipment boots have been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors. Dependable. Durable. Engineered and tested to the highest standards.