Feature 1, Specially designed to check the compression pressure of gas in the cylinder. 2, Selection of premium grade material, durable and long lasting; Various specifications, complete configuration. 3, Double-scale pressure gauge, clear scale, with vent valve, easy to use. 4, Quick connector is easy to insert and remove, corner design, easy to use. 5, Includes multiple adapters that fit for GM, Ford, Lincoln, Isuzu, MercedesBenz, Kubota, Peugeot . Features: Specially designed to check the compression pressure of gas in the cylinder. Selection of premium grade material, durable and long lasting; Various specifications, complete configuration. Double-scale pressure gauge, clear scale, with vent valve, easy to use. Quick connector is easy to insert and remove, corner design, easy to use. Includes multiple adapters that fit for GM, Ford, Lincoln, Isuzu, Mercedes-Benz , Kubota, Peugeot . Specification: Pressure Gauge Diameter: 75mm / 3inch Measuring Range: 0-1000psi Hoe to Use: 1. Start the engine and run to the normal working temperature, turn off the engine and wait for the engine to stop running, remove all the spark plugs; 2. Fully open the throttle valve and press the connector of the pressure gauge against the spark plug hole; 3. Use the motor to drive the engine to rotate at 100-150R/MIN for 3-5 seconds. At this time, the pointer on the gauge will gradually rise, and will stop when a certain value is reached. The indicated value at this time is the compression pressure of the cylinder; 4. Press the button to reset the pointer to zero; 5. Repeat the steps above for 2~3 times to improve the measurement accuracy; 6. The cylinder pressure of general cars is >0.9MPA, and <8% (the pressure difference of each cylinder, the gasoline engine does not exceed 8% of the average pressure of each cylinder). If the measured value is less than the specified value, and the intake system is normal, it may indicate that the cylinder and the piston, the cylinder cover have leakage. The possible causes are the wear and ablation and other unfavorable condition of the cylinder, piston, valve and piston ring. If the measured value is greater than the specified value, and the intake and exhaust system is normal, the possible cause is the serious accumulation of the combustion chamber. Package List: 1 x Compression Pressure Gauge 1 x Air Release Button 1 x Rubber Hose 1 x 1/8 inch NPT Quick Coupler 3 x 7/16inch-20(F) Quick Coupler 3 x M12x1.25(M) - 7/16inch-20(M) Adaptor 2 x M12x1.25(F) - M18x1.5(M) Adaptor 1 x M10x1.25 Adaptor Short (TU-15-14) 1 x M10x1.25 Adaptor long (TU-15-3A) 1 x ZG 1/8inch(M) - Male Quick Coupler 1 x ZG1/8inch(F) - M24x2(M) Adaptor (TU-15-4A) 1 x Adaptor Sleeve 1 x Quick Connect with Ball Tip 1 x 1/2inch-19 Lock Nut 1 x 7/16inch-20(M) - 7/16inch-20(F) 90 1 x ZG1/8inch(M) - M24x1.5(M) Adaptor 1 x M10x1(M) Adaptor (TU-15-1A) 2 x Copper Washer Note:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.