Z Premium Hydraulic Oil 68-20, Premium quality, shear stable, multi-viscosity, anti-wear hydraulic fluid, designed for use in hydraulic systems subjected to wide variations in ambient and operating temperatures. They provide long service life and are recommended for hydraulic and circulation systems of a wide variety of equipment. These oils are also used for compressor crankcase lubrication, but are not recommended for lubrication of turbines and equipment having silver-coated components.