Specially designed for deep seated spark plug ports with long narrow threads, as found on many modern petrol engines Includes M12 and M14 spark plug adaptors - M12 spark plugs are now commonly being used by: Alfa Romeo, Audi, BMW, Citreon, Dacia, Fiat, Ford, Hyundai, Jaguar, Kia, Land Rover, Mercedes, Mini, Nissan, Peugeot, Renault, Seat, Skoda, Smart, Toyota and VW Positive lock - quick release connector, ensures adaptors cannot accidentally be left in the spark plug port Specially designed self-centering adaptors ensure minimal risk of cross threading when attempting to screw the compression adaptor in to the spark plug port Gauge Scale: 0 - 20bar, 0 - 190psi