Miller® HD Nitrogen regulator, 0-275 PSIG - Series 40™ Heavy-Duty Single-Stage regulator regulators are extremely durable and contain our exclusive Sure Seat™ filtered seat technology for extended seat and regulator life in the most demanding industrial applications. They feature a stainless steel diaphragm which allows for use with liquid gases, all brass construction which will stand up to corrosive atmospheres and 2.5-inch (64 mm) brass case gauges.