The Mercedes Benz V6 and V8 engines DO NOT provide much room to safely replace the wire set. Also, over time the spark plug boot may adhere to the spark plug making it even tougher to remove the wire set in this limited workspace. Our new redesigned spark plug connectors provide a bearing area which allows the installer to use the factory tool to easily remove or install the wire set. The OE connector is 16mm in diameter, but because it has a seam, it becomes 22mm when you rotate it 90 degrees. The Factory wrench has a 17mm opening so the installer must rotate the wrench to find the proper fit. Bremi has improved the design over the OE connector by allowing the factory tool to fit properly at any angle because it is 14mm all the way around.