WIKA 4233761 Commercial Sprinkler Pressure Gauge, Dry-Filled, Copper Alloy Wetted Parts, 4" Dial, 0-300 psi Range, +/-3/2/3% Accuracy, 1/4" Male NPT Connection, Bottom Mount Copper alloy wetted parts for high corrosion resistance against salty liquids Circular dial is four inches in diameter and enclosed in a polycarbonate plastic case for increased durability Measures up to 80 psi for air pressure and up to 300 psi for water pressure Display accuracy is + or - 3/2/3 percent of span over the entire range of the gauge (ASME B40.100 Grade B) Lower mount male connection with 1/2" NPT rate