The 2-1/2" dial on these DuraChoice liquid filled pressure gauges is readable from a considerable distance. The stainless steel case protects against harsh environments and the glycerin filling promotes longer service life because it helps dampen vibration and pulsation. The glycerin also discourages condensation from forming and obscuring the readout. As far as manometers go, this is a great choice for water, oil, gas (WOG), diesel or other hydraulic applications.