LPG4-D9022N is a series LPG4 2.5" low pressure gauge which offers top of the line performance and accuracy for pressure and Vacuum applications. The LPG4 is constructed from a single beryllium-copper diaphragm affixed to a precision machined brass plate. This innovative design, together with a high-precision, milled-teeth brass movement and nickel-silver pinion and bearing surface, provide the user with a top of the line low pressure instrument. Typical applications include air flow indication, liquid level and draft measurement.