This VW/Audi wrench is actually two tools in one... This durable, high quality chrome vanadium steel tool allows the technician to use one end while removing the transmission drain plug and the other end to remove the oil drain plug. The Transmission Drain Plug is a M16 commonly used on VW/Audi and Porsche. The Oil Drain Plug side is a 19mm Box Wrench which works late model VAG cars.