Round Boiler Gauge Boiler Gauge Nominal Size 2 1/2 in Gauge Connection Location Center Back Gauge Connection Type MNPT Gauge Connection Size 1/4 in 0 to 75 psi Gauge Accuracy +/-3-2-3 Percent Basic Gauge Case Material Steel Basic Gauge Wetted Parts Brass / Bronze Basic Gauge Lens Material Plastic 60 Degrees to 260 Degrees Boiler Gauge Temp Range - F Temp Range (C) 20 Degrees to 120 Degrees Temp Accuracy +/-3 Percent Case Material Steel Case Color Black Socket Material Brass