The meter can measure the differential pressure conveniently. It features 11 selectable units of measure, and used for testing ventilation and air conditioning system, spot check, clean room, or any gas pressure system troubleshooting.Features:Large LCD backlight display, providing clear reading.11 selectable units for measurement, convenient for use.Max./Min./Average values, and with a relative time clock.Low battery indicator and pressure unit indicator.Zero adjustment, offset and DIF function.Data hold and automatically shutdown function.Specification:Model: HT-1890Display: LCD BacklightInH2O Range: 55.40; Resolution: 0.01Psi Range: 2.000; Resolution: 0.001Mbar Range: 137.8; Resolution: 0.1Kpa Range: 13.79; Resolution: 0.01InHg Range: 4.07; Resolution: 0.001MmHg Range: 103.4; Resolution: 0.1Ozin2 Range: 32; Resolution: 0.01FtH2O Range: 4.612; Resolution: 0.001CmH2O Range: 140.6; Resolution: 0.1Kgcm2 Range: 0.140; Resolution: 0.001Bar Range: 0.137; Resolution: 0.001Accuracy: 0.3%FSO(25C)Repeatability: 0.2%(Max. +/-0.5%FSO)Linearity/Hysteresis: 0.29%FSOMax. Pressure: 10Psi Response Time: 0.5s Typical Low Battery Indicator: YesOver Range Indicator: Err. 1Under Range Indicator: Err. 2Operating Condition: 0~50C / 32~122FStorage Condition: -10~60C / 14~140FPower Supply: 1 * 9V Battery (NOT Included)Size: 16*5.5*3.2cm/6.3*2.2*1.3inWeight: Approx.268g/9.5ozPackage List:1 * Digital Manometer(Battery NOT Included)1 * Black Pouch4 * Flexible Tube1 * Metal Accessory1 * User Manual (English).