Handheld Digital Manometer, Maximum Pressure 4 in wc, Minimum Pressure 0 in wc, Pressure Accuracy +/-0.5 Percent, Process Connection Size 1/8 in, 3/16 in, Process Connection Type Hose Barb, Includes Batteries Yes, Digital Display Features 4 Digit LCD, NIST Traceable Certificate No, Series 475, Pressure Units in wc, psig, Air Velocity Accuracy +/-0.5 Percent Full Scale from 60 to 78 Degrees F, +/-1.5 Percent Full Scale from 32 to 60 Degrees F and 78 to 104 Degrees F, Application Air; Natural Gas