Specifications: The HT-1890 Digital manometer measures gauge/differential pressure from -55H2O to +55H2O(2 psi).It features 11 selectable units of measure: in H2O,pis,bar,mbar,Kpa,inHg,mmHg,ozin2, ftH2O,kgcm,additional features include data hold and auto power off disabled,careful use of this meter will provide years of reliable service. Features: 1.11 selectable units of Measure 2.Max/min/average, and with a relative time 3.large LCD Back light dual display 4. Zeroing,offset,and data compensation 5.Low battery display and automatic shutdown 6.Data Hold and Error code Package included -1 x Manometer -2 pairs of tubing -1 x 1/8" MPT x 1/8" Barb Access Fitting -1 x Soft pouch -1 x Instruction Manual