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