2 – 1/2″ (63mm) one piece die cast Brass Plated case and Brass socket, Glycerine Filled. 1/4″ NPT Connection with 17mm wrench flats cast into Stem Mount, Lower Connected. Ring is highly polished brass. Window is polycarbonate. Bourdon Tube is phosphorus Bronze for gauges with ranges up to 8000 PSI, AISI 316L Stainless Steel above 8000 PSI. C-tube configuration is used below 900 PSI, spiral tube for higher ranges. Movement features all Brass gear and plates. Pointer is balanced black aluminum, non-adjustable. Dial is white aluminum with black markings. Markings and graduations in accordance with ASME B40.1-1998. Accuracy is 1.5% of full scale. Options include Chrome Plated Steel Front Flange, Chrome Narrow bezel with U-Clamp. Additional Options are available. Contact Customer Service for assistance regarding options and ordering.