Round Boiler Gauge, Boiler Gauge Nominal Size 3 in, Gauge Connection Location Bottom, Gauge Connection Type MNPT, Gauge Connection Size 1/2 in, 0 to 100, psi, Gauge Accuracy +/-3-2-3 Percent, Basic Gauge Case Material Steel, Basic Gauge Wetted Parts Copper, Basic Gauge Lens Material Plastic, 80 Degrees to 320 Degrees Boiler Gauge Temp. Range - F, Temp. Range (C) 20 Degrees to 160 Degrees , Case Material Steel, Case Color Silver, Socket Material Copper Alloy, Tube Material Copper Alloy WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov - Nickel (Metallic)