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