Liquid Filled Center Back Mount Pressure Gauge with 4″ Dial, 0-600 PSI, 1/4″ Male NPT Connection, Stainless Steel CASE and Bezel. LIQUID/GLYCERIN FILLED GAUGES ARE SPECIFICALLY DESIGNED FOR APPLICATIONS WHERE VIBRATION AND PULSATION IS PRESENT. CENTER BACK MOUNT GLYCERIN FILLED PRESSURE GAUGE, FACE/DIAL SIZE 4″, 1/4″ MALE NPT CONNECTION, 0-600 PSI RANGE. PLEASE NOTE: 1/4″ MALE NPT MEASURES 0.540″ OUTSIDE THREAD DIAMETER. THESE ARE INDUSTRIAL GAUGES AND NOT DEEMED LEAD FREE. DO NOT USE WITH POTABLE WATER APPLICATIONS. GLYCERIN FILLED, POLYCARBONATE LENS, STAINLESS STEEL CASE & BEZEL, COPPER ALLOY INTERNALS, BLACK ALUMINUM POINTER, DESIGN MEETS OR EXCEEDS ASME B40.100 PRESSURE GAUGE STANDARD. 3/2/3% ACCURACY, AMBIENT TEMPERATURE -50f TO 160f, SEE ADDITIONAL PICS FOR DIMENSIONAL DATA, PSI/BAR. APPLICATIONS INCLUDE OIL, WATER, AIR, COMPRESSOR, HYDRAULICS, HVAC, GASEOUS & LIQUID MEDIA THAT ARE NOT HIGHLY VISCOUS OR CRYSTALLIZING AND NOT CORROSIVE OR OXIDIZING TO COPPER ALLOY PARTS. INDUSTRIAL GAUGE SPECIFICATIONS_ LENS: PLASTIC, WETTED PARTS: COPPER ALLOY, CASE: STEEL, POINTER: BLACK ALUMINUM, ASME B40.1 GRADE B.