United Electric 120 Differential Pressure Switch - 1 SPDT Switch Output. Adjustable Range: 10 to 100 PSID. Working Pressure: 30" HgVac to 180 PSI; Proof Pressure: 300 PSI. Deadband: 0.5 to 2 PSI. Internal Adjustment, Dual Conduit, Welded 316L Stainless Steel Bellows and 1/2" NPTF Pressure Connections. Epoxy-Coated Diecast Aluminum NEMA 4X Enclosure for Class I, Div 1 and Class II, Div 1 Use