Best in USA Liquid Filled 2.5" Air Pressure Gauge Center Back Mount 1/4" NPT 2-1/2" Dial - 0 to 200 PSI Dial size: 2.5" Connection size: 1/4" male NPT which measures about 1/2" in diameter. Accuracy: 3-2-3% ANSE40.1 Compliant Ambient temperature: 30 F to 160 F