Features: 1) New Brand Vacuum Gauge: Used to test system leak and discern vacuum pump quality of the evacuation in an HVAC and refrigeration system; accurate measurements from 19,000 Microns (atmosphere) to 0 Micron; 2) Free App (ioS and Android): Settable high/low-pressure alarm, you can receive remote notifications when readings move beyond a predetermined value. The data could be recorded and exported in Excel and PDF format; 3) Long Transmission Distance: Elitech Pressure Gauge App is connected by wireless Bluetooth technology, up to 1187' in ideal conditions (no obstructions); 4) Rubberized water-resistant housing (IP65 Rated); ensure a deep vacuum throughout the entire system and prevent the mist when the refrigerant caused by refrigerant bottle blasting; 5) Multiple units: Easy conversion between 8 measurement units: inHg, Torr, psi, mbar, mTorr, Pa, micron, Kpa.