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-1890 Display: LCD Backlight InH2O Range: 55.40; Resolution: 0.01 Psi Range: 2.000; Resolution: 0.001 Mbar Range: 137.8; Resolution: 0.1 Kpa Range: 13.79; Resolution: 0.01 InHg Range: 4.07; Resolution: 0.001 MmHg Range: 103.4; Resolution: 0.1 Ozin2 Range: 32; Resolution: 0.01 FtH2O Range: 4.612; Resolution: 0.001 CmH2O Range: 140.6; Resolution: 0.1 Kgcm2 Range: 0.140; Resolution: 0.001 Bar Range: 0.137; Resolution: 0.001 Accuracy: 0.3%FSO(25C) Repeatability: 0.2%(Max. +/-0.5%FSO) Linearity/Hysteresis: 0.29%FSO Max. Pressure: 10Psi Response Time: 0.5s Typical Low Battery Indicator: Yes Over Range Indicator: Err. 1 Under Range Indicator: Err. 2 Operating Condition: 0~50C / 32~122F Storage Condition: -10~60C / 14~140F Power Supply: 1 * 9V Battery (NOT Included) Size: 16*5.5*3.2cm/6.3*2.2*1.3in Weight: Approx.268g/9.5oz Package List: 1 * Digital Manometer(Battery NOT Included) 1 * Black Pouch 4 * Flexible Tube 1 * Metal Accessory 1 * User Manual (English)