8MILELAKE Professional Petrol Gas Engine Cylinder Compression Tester Gauge Kit Auto Tool Adapters for a wide number of vehicles (spark plug types/depths) Includes 2 rubber cones ends for quick check (no need to thread into head) 3" Gauge has dual color scale with 0-300 PSI, 0-20 kPa Fittings: M10, M12, M14, M18 (Male, With "O" Ring) Includes 14mm and 18mm spark plug adapters Check valves and rings, inspect for carbon buildup and late timing. Adapters for a wide number of vehicles (spark plug types/depths) Kit includes 2 rubber cones ends for quick check (no need to thread into head) 3&#034; Gauge has dual color scale with 0-300 PSI, 0-20 kPa Gauge will hold pressure values and has quick push button release valve Fittings: M10, M12, M14, M18 (Male, With &#034;O&#034; Ring) Includes 14mm and 18mm spark plug adapters Diam: 3&#034; Dual  scale: 0-300 PSI, 0-20 kPa Better Air Sealing: Rubber protective cover &amp; authentic copper check valve 4 Fittings Covers Most vehicles M10*1.00MM; M12*1.25MM; M14*1.25MM; M18*1.50MM Size: 14mm&amp;18mm Includes 2 rubber cones ends for quick check (no need to thread into head) 1/2&#034; diameter x 14&#034; extension hose