Male threaded mount round dial arabic number. Measure air pressure 0~1200Kpa 0~180PSI 0~ 12kg/cm2. The blue line is for marking the Kpa the red line is for marking the Lb/in2 and the black line is for marking the kg/cm2. It is Installed mainly on the pneumatic pipe and other auxiliary equipment. Used to measure pipeline and container no explosion danger no crystals not for alloy solidification and do not corrode liquid gas.