This unit is brand new with the option to buy all 8 here are some specs I found online: Ashcroft 1009 Industrial Pressure Gauge, 1/2" MPT, 0 to 100 PSI, +/-1% Accuracy, 4-1/2" White Aluminum Dial, Micrometer Adjustable Pointer, 316L Stainless Steel Bourdon Tube/Socket, 304 Stainless Steel Case/Bayonet Ring, Glass Window, 400 Stainless Steel Movement, Dry, Lower, Open Front, Single Scale, Industrial Pressure Gauge with Stainless Steel Tag Wired. Manufacturer: Ashcroft Application: Deionized Water, Hydraulic, Pneumatic, Refrigeration, Specialized OEM Equipment Connection Location: Lower Mount Dial Color: White Dial Material: Aluminum Dial Size: 4-1/2 in. Display Type: Dial Enclosure Material: 304 Stainless Steel Full-Scale Accuracy: 1% Max. Pressure: 100 psi Min. Pressure: 0 psi Mounting Type: Panel Pointer Type: Micrometer Adjustable Sensor Element: AISI 316L Stainless Steel Bourdon Tube/Socket Temperature Rating: -20 to 200 F (Ambient), -20 to 250 F (Process), -40 to 250 F (Storage) Connection Size: 1/2 in. IP Rating: IP54 Product Category: Pressure Gauges Product Type: Stainless Steel Gauges Connection Type: MNPT Filled: Dry Case: 304 Stainless Steel Pressure Range: 0 to 100 psi