Black steel case in 2.5″ dial option and chrome-plated steel case in 4″ dial option. Both dial sizes have a steel tube and socket in ¼” NPT lower connections. Commercial grade full scale accuracy of 1.6%. A dry case style with a plastic screw on lens. Factory stock in both of the standard ammonia pressure/temperature ranges- Range: 30″ Hg to 150 PSI w/ corr °F and Range: 30″ Hg to 300 PSI w/ corr °F.