1This product has 11 air pressure units and is fully functional 2Differential pressure measurement is ideal for measuring ventilation and air condition systems 3With maximum, minimum, average pressure value recording and viewing capabilities, and data retention features 4Large with backlit display for clearer data display 5There is a low battery prompt function, you can choose the automatic shutdown function, overrange prompt function and calibration functionFeatures: This product has 11 air pressure units and is fully functional. Differential pressure measurement is ideal for measuring ventilation and air condition systems. With maximum, minimum, average pressure value recording and viewing capabilities, and data retention features. Large with backlit display for clearer data display. There is a low battery prompt function, you can choose the automatic shutdown function, overrange prompt function and calibration function. Specifications: Condition: 100% Brand New Material: Plastic Range: +2psi Accuracy: 0.3% FS Linearity/hysteresis: 0.1% of full scale FS Repeatability: 0.25% FS Pressure connection: two 1/8" (3.18 mm) quick connectors Working temperature: 0~40C Storage temperature range: -10~60C Product size: approx. 150 x 55 x 30mm / 5.9 x 2.2 x 1.2in Battery type: 9V battery (Battery not included) Package list: 1 x Digital pressure gauge(Battery not included) 2 x Plastic hose 1 x Metal connector 1 x Portable bag 1 x English manual Note: 1.Please allow 0-1 inch error due to manual measurement. Thanks for your understanding. 2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.