The CPAP Pressure Meter is a small lightweight device that can be used to verify the pressure on your CPAP/BiPAP system. The Pressure Meter connects directly to any standard CPAP tubing without adapters or additional tubing and can be read just like a traditional flow meter. Please note, the CPAP Pressure Meter should only to be used to verify pressure, not as a calibration device. Part AGCPM100 – Accurate to +/- 2CM H2O. For the most accurate reading of your system pressure please visit your healthcare provider.