Specifically designed for the fire sprinkler industry. Bourdon tube pressure gauges with black polycarbonate case. Snap-in clear polycarbonate window, 4" face. White aluminum dial with stop pin, black and red markings. Black aluminum non-adjustable pointer. 1/4" NPT lower mount. ASME B40.1 Grade B (+3/2/3% accuracy). UL listed and FM approved for fire sprinkler service. Ambient temperature Range: -40 degree F to 140 degree F.