Applications Used for hydraulic and pneumatic systems Compressors,compressed air system Suitable for fluid medium which does not clog connection port Used for providing protection from vibration and pulsation. Case:Stainless Steel Ring:Stainless Steel Window:PC Socket & Connection:Brass Movement:Brass Bourdon Tube:Brass Pointer and Dial:Aluminum Liquid:Glycerin,Sillicone Range:Vacuum,Compound 0 to 6000 psi Class:1.6% Flange:Stainless Steel U-Clamp:Stainless Steel Mounting Type:Back