The TIF3420 easily takes differential pressure readings with the dual input pressure manometer. Use to measure differential, absolute and static pressures in most HVAC systems. Chose the units of measure your most comfortable with – 11 selectable units of measure to choose from. Store MIN/MAX and AVG readings. Rugged design that is easy to grip and hold. Large easy to view LCD display is easy to read from a distance. Zero function lets you correct for any offsets in readings or measurements.