Ametek Crystal M1 [M1-100PSI-AXX-W] Digital Pressure Gauge, 1/4" NPT male, 0 to 100 PSI w/Pump System A (Pneumatic) 0 to 2 bar  &  Waterproof Case. The Crystal M1 Pressure Gauge maintains 0.2% of reading accuracy from -10˚ to 50˚C. Accuracy is not affected by dropping, over-pressure, vibration, temperature, or rapid pressure change.