Bosch 7547 (WSR6F) Spark Plug, Pack of 2 Nickel-Plated Rolled Threads Provide Anti-Seize and Corrosion Protection Tapered Cut Nickel Chromium Ground Electrode Assists in Cold Weather Starts and Provides Increased Ignitability Angular, 5-Rib Insulator Design Prevents Flashover Thread Size: 14mm; Thread Pitch: 1.25mm Removable Terminal Nut