GM Genuine Parts Glow Plugs are specially designed to give diesel engines the heat they need for cold starts, and are the high quality replacement ideal for many vehicles on the road today. GM Genuine Parts Diesel Glow Plugs are designed, engineered, and tested to rigorous standards, and are backed by General Motors. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE) GM regularly updates production and service part designs to integrate new materials and technologies These are single glow plugsview less