GAUGE Stainless Steel Back Mount Liquid Filled Pressure, 2.5" FACE / DIAL, Rated WOG, 1/4" Male NPT, Range 0 - 30 PSI (Qty 01) 0-30 PSI LIQUID / GLYCERIN FILLED, 1/4" MALE NPT ( 1/4" NPT Measures 0.505" outside thread diameter in inches) BACK MOUNT CONNECTION, 2.5" DIAL / FACE, 304 STAINLESS STEEL CASE AND BEVEL BRASS INTERNALS AND CONNECTION, 1.5% DEGREE OF ACCURACY, PLASTIC LENS DUAL SCALE SHOWS BOTH PSI AND BAR, AMBIENT TEMPERATURE: MINIMUM -30deg F THROUGH 160deg F MAX