Actrons CP7827 Compression Tester Kit is an ideal tool for detecting worn piston rings, burnt valves, and blown head gaskets in engines of all types - automotive, motorcycle, ATV, farm/fleet, and more. Convenient push-button side release valve allows repeated testing without the need to disconnect between tests saving you valuable time and elimating the hassle. Gauge features a 2-1/2 inch diameter, easy-to-read face with standard and metric scales: 0-300 PSI and 0-2100 kPa. The 17 inch, high-pressure, flexible oil and grease resistant hose features a quick release connection at the gauge for faster, easier use. 14mm and 18mm ends fit most spark plug thread sizes. Included 14mm long reach adapter is perfect for many late model vehicles wth deeply recessed spark plugs. Note: it is very important to ensure that adapters are securely tightened to the hose to prevent possible separation when removing the adapter from the cylinder head. Includes comprehensive instructions in English, Spanish, and French..