Designed for use in numerous applications and industries, these digital gauges can be used for air pressure measurement in marine and diving, filtration, compressor and Pneumatic regulators measurement, laboratory vacuum and pressure measurement, as well as Aviation and defense, and general OEM use where air or compatible gases are used and Brass can be used. These high-accuracy, low-cost digital gauges have a four-digit, 1/2 inch H LCD and read in psi, bar, MPa, and kg/cm2. Gauges have a 1 3/4 inch (44.5 mm) dial and come in three styles - 0 to 145 psi in 1/8 inch or 1/4 inch NPT) connection, and vacuum to 100 psi in 1/8 inch NPT) connection. What's included: 3 V lithium battery. Compact gauges provide accurate readings for lab and process environments Brass Centre back-mount process connections single-button function for on/units/off five-minute auto power-off preserves battery life