Double Manifold Gauge Set (R410A/R32/R22/R507A/R-134a)
The manifold pressure gauge for measures the pressure of the gas/air mixture within the intake manifold of the compressor.
-An HVAC manifold set has two gauges, blue and red. The blue is for low pressures, and the red is for high pressures. The red and blue valves on the side turn on and off to control gas going to the low and high-pressure valves.