Prokomon Engine Cylinder Leak Down Tester Kit;Gasoline Engine Leakdown Tester Kit with Extension Rod;Cylinder Leakage Tester Set for Pressure Check and Leakage Rate Test. Engine Cylinder Leak Down Tester: Leakdown gauge tool hooks up to air compressor(prepare by yourself) can help to detect common engine faults such as worn piston rings, worn valves, cracks in cylinder walls and blown head gaskets.