General description This is a brass short reach adaptor designed for use with compression testers. It allows compatibility with various spark plug sizes on different vehicles, making testing easier and more versatile. Technical specifications Internal thread size: 14 x 1.25mm External thread sizes: 10 x 1.00mm and 12 x 1.25mm Compatibility and accessories Compatible with petrol compression testers Suitable for vehicles with M10 and M12 threaded spark plugs Commonly used on BMW, MINI, Alfa Romeo, and Jaguar vehicles Installation Attach the adaptor to the compression tester Screw it into the spark plug port of the vehicle Usage Use during compression testing to adapt to different spark plug thread sizes