Bosch's Professional Compression Tester Kit is an ideal tool for detecting worn piston rings, burnt valves, and blown head gaskets on most foreign and domestic vehicles, small engines, motorcycles, snowmobiles, and ATVs. Convenient push-button side release valve allows repeated testing without the need to disconnect between tests saving you valuable time and eliminating the hassle. Gauge features a 2-1/2 inch diameter, easy-to-read white face with standard and metric scales: 0-300 PSI and 0-2100 kPa, highly accurate Bourdon Tube movement, and heavy-duty rubber boot. The 17 inch, high-pressure, flexible, oil and grease resistant hose features a quick release connection at the gauge for faster, easier use. Includes adapters for most standard spark plug thread sizes: 10mm, 12mm, 14mm, 14mm long reach, and 18mm plus a handy repair kit with valves and rubber O-rings. Note: it is very important to ensure that adapters are securely tightened to the hose to prevent possible separation when removing the tester from the cylinder head. Includes comprehensive instructions in English, Spanish, and French. 1 year .