Pressure/Vacuum Generator, For Use With Manometer, Multimeter, Function Calibrate or Test HVAC Air Flow Sensing Switches Set Points, +/-0.1 to +/-12.0 in WC, 1/8 and 1/4 Adapter Thread Fitting (F)NPT, Features Constant Air Source, Fine Tune Output Adjustment Potentiometer, Handheld, Operating Temperature 50 Degrees to 120 Degrees F, Battery Type (3) AA, Includes Batteries, Hand Held Attached Case, Tubing Kit