ApplicationTo check leakage amount in 4-stroke engines To detect engine faults like cylinder head cracks,worn valves or piston rings Display percentage of cylinder leakage & pressureSpecificationPackage Includes: Engine Cylinder Leak Tester Kit Gauge Scale: 0-100PSI in 5% increments Spark Plug Adapters: 10mm, 12mm,14mm Metric Adapter: M12x1.25, M14x1.5 2-1/2\" input pressure gauge compatible for Case Color: random shippedNoteNo Instruction Included. Please feel free to contact us for whatever we can help.