Review on Engine Compression Cylinder Pressure 0 300PSI by Reed Nuttbrock

Unfortunately due to the low price I should have known better but I figured the compression tester isn't that much so maybe that's ok. mine doesn't hold the pressure, the gasket material is very weak and the pressure escapes so you can't get an accurate reading. I only test jet ski compression from 75 to 130 pounds. it's better to seal them anyway, no luck, next time I'll buy a much more expensive brand