The Dwyer 2100 Magnehelic Pressure Gauge is a high-quality differential pressure gauge designed for measuring pressure in inches of water (in H2O). With a range of 0 to 100 inches, this gauge is perfect for HVAC and refrigeration applications. It features a durable die-cast aluminum body, a 4 1/2 inch nominal dial size, and a 1/8 inch FNPT gauge connection. The Magnehelic Pressure Gauge also has an operating temperature range of 20 to 140 degrees Fahrenheit and a gauge accuracy of +/-2.00 percent. Made in the US by Dwyer, this pressure gauge is a reliable tool for precise measurements in various industrial settings.