For easy and quick measurement of the maximum peak pressure of engines. Consists of three major components: a check valve, a pressure gauge and an exhaust valve. The maximum peak pressure is directly read on the dial when the indication has settled. There is no need for diagram acquisition, area measurement with a planimeter, or length measurement with a scale. Oil-filled pressure gauges are used as indicators to provide outstanding vibration-resistant and heat-resistant characteristics. The internal pressure is released to zero by opening the exhaust valve after measurement.