Dwyer 2300-20CM Magnehelic® Differential Pressure Gauge is a durable and reliable gauge designed for air and non-combustible, compatible gases. It has an accuracy of ±2% throughout the range at 70°F and an IP67 enclosure rating. The gauge features a die-cast aluminum case and bezel with an acrylic cover, and its exterior finish can withstand a 168-hour salt spray corrosion test. It has a 4" diameter dial face and comes with standard accessories such as pressure taps and adapters. The gauge has a pressure limit of -20 in Hg to 15 psig and is designed for diaphragm mounting in a vertical position.