Mid-West Instrument P/N 120-AA-10-OO 0-50 PSID, Model 120, 2.5" Dial, 0-50 PSID DP Range, Plastic Case, Aluminum Body, Stainless Steel Piston Wetted Parts, 1/4"FNPT Back Connections, 3000 PSIG Max. Working Pressure, 2% of FS Ascending Accuracy, Piston-Typ