Pressure Gauge mBar Diameter Ø 160 mm

What is a millibar pressure gauge?
Low pressure gauges (in millibar) | Manometer
This type of pressure gauge always has a scale in millibars, because pressure in a vacuum is always
somewhere between 0 and 1 bar. Fluids or gases that work at low pressure values, can also be
measured with a low-pressure gauge in millibar.