Digital Manometer, Maximum Pressure 15 in wc, Minimum Pressure -15 in wc, Accuracy +/-1.00 Percent of Reading, Process Connection Size 3/16 in, Process Connection Type Hose Barb, Batteries Included Yes, Digital Display Features Digit Backlit, NIST Traceable Certificate Yes, Series DP-CALC, Alarm No, Application Air, Batteries Required Yes, Battery Type (4) AA, Calibration Certificate Included NIST, Data Hold No, Display Units hPa, in H2O, kPa, mm Hg, Pa, For Tubing Diameter 3/16 in