Applications Used for hydraulic and pneumatic systems Compressors,compressed air system Suitable for fluid medium which does 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:Brass Pointer and Dial:Aluminum Liquid:Glycerin,Sillicone Range:Vacuum,Compound 0 to 6000 psi Class:1.6% Mounitng Type:Bottom