Application: Water, Oil, Air & Hydraulic Application Dial Size: 2-1/2 inches Dial Size (Crimped Casing) Accuracy: +/- 3/2/3 Percent Scale: Dual Scale - PSI / Bar Movement: Copper Alloy Bourdon Tube: Copper Alloy Window: Polycarbote Case: Stainless Steel case for protection in harsh environments Connection: Copper Alloy Lower Mount; 1/4 inches NPT (for 2-1/2 inches dial) Normal Ambient Temp.: -4F to +140F (-20C to +60C) Liquid Filling: Glycerin oil filled to enhance the reliability and integrity; helps dampen the effect of vibration and pulsation; lubricates the movement and extends the life of gauge.