Product 1.[High Accuracy andamp Resolution]: The digital manometer can measure 2.999Psi or (0.001 resolution) with accuracy 0.3 percent in full scale. 2.[Dual Tube Connectors]: Comes with Positive andamp Negative pressure tube connectors, which can easily measure differential pressure with its dual input probes. 3.[12 Measure Units Available]: 12 kinds of units for your needs, including Kpa, Psi, kgcm2, ozin2, Bar, mbar, inHg, mmHg, inH2O, ftH2O, cmH2O, Pa 4.[Max andamp Min Button, Back-light, Data Hold, Auto-off]: The AUTOOL digital manometer is tailor-made with all of these useful features for your work requirements Great tool for homeowners and handymen. 5.[Wide Applications]: Best used for HVAC, pneumatic control, medical equipment, gas appliance service and installation, laboratory testing, computer peripheral. Easy to use and accurate with a large display. Specifications: Measuring range: 20.68Kpa or 2.999PSI Measure Accuracy: 0.3 percent FSO (25) Repeatability: 0.2 percent (Maximum 0.5 FSO) Linearity or hysteresis: 0.29 FSO(25) Response: Typical 0.5s Up overload indication: Err0 Down overload indication: Err1 Operating temperature: 0-50 Storage temperature: -10-60 Power Supply: 9V battery no include Package includes: 1pcsx AUTOOL Digital Manometer main unit 2pcsx Tubes 1pcsx Fitting 1pcsx Package box 1pcsx User manual