Copper alloy wetted parts for high corrosion resistance against salty liquids Circular dial is three inches in diameter and enclosed in a forged brass case for increased durability in corrosive environments Pressure ranges from 15 psi to 15,000 psi Display accuracy is + or - 2/1/2 percent of span over the entire range of the gauge (ASME B40.100 Grade A) Lower back mount male connection with 1/4" NPT rate