Ametek APM [APM300PSI] CPF Pressure Module 300 psi with 1/4" NPT Pressure Fitting and 0.025% Accuracy. The Ametek APM CPF Series portable pressure modules offer the functionality and flexibility to perform pressure calibrations with a multifunction signal calibrator. Or, combine with a hand-help pressure calibrator to expand its range. The APM delivers the same high level accuracy whether in the lab or in the field.