One new top quality liquid filled 1/4" npt center back mount 0-100 psi air pressure gauge. This gauge has a glycerine filling that helps dampen the effects of pulsation and vibration, while also perpetually lubricating the movement, and keeping contaminates such as dirt away from all moving parts, which will extend the life of the gauge. This gauge also has a blue pressure relief vent that needs to be pulled up before use. This gauge reads at 0, 20, 40, 60, 80, 100 psi with line markings every 2 psi. Bar reading at 0-7. Click on the Technical Specs tab for more information.