Wallace and Tiernan branded pressure gauges are glycerin filled For resistance to heat, vibration and pulsation. Gauges have 316(L) stainless steel sockets and bourdon tubes For enhanced corrosion resistance and use in high purity applications. Gauge face has dual psi and bar scales and is protected by a clear polycarbonate window. Specifications: Dial: 2. 5" (63 mm) with white background Scale: Two Color Dual Scale Primary scale - PS Primary scale and pointer to be black Secondary scale - BAR / x100= scale to be blue Accuracy: ASME B40. 100; Grade B 3-2-3%Connection: 1/4" Male NPT, bottom mount Socket Material: 316(L) Tube Material: 316(L) Material: 300 Series Material: 300 Ring Material: 300 Series Material: Polycarbonate Liquid Fluid: Glycerin fill - Shall remain visually clear For 5 years Fluid Temperature: 212F Maximum Ambient Temp: -4F to 140FIncludes NIST traceable calibration certificate