Handheld Digital Manometer, Maximum Pressure 15 in wc, Minimum Pressure -15 in wc, Pressure Accuracy +/-1 Percent of Reading, Process Connection Size 3/16 in, Process Connection Type Hose Barb, Includes Batteries Yes, Digital Display Features Backlit LCD, NIST Traceable Certificate Yes, Series DP-CALC, Maximum Air Velocity 15,500 fpm, Pressure Units in H2O; mm Hg; Pa, Air Velocity Accuracy +/-1.5 Percent at 10.16 mps, +/-1.5 Percent at 2000 fpm, Air Velocity Resolution 1 fpm, 0.1 mps