Robinair Premium High Vacuum Pump Oil is engineered to maintain maximum viscosity at high running temperatures and to improve cold weather starts. Laboratory tests prove that Robinair oil is more thermally stable in comparison to other leading brands, which means it resists breaking down due to heat for a longer period of time. Robinair oil has a lower moisture content than other oils thanks to our special packaging and handling procedures. Moisture degrades the oil's purity, thinning it and reducing the pump's ability to reach a deep vacuum. Because the quality of your vacuum pump performance is directly related to the quality of vacuum pump oil used, only use an oil that is proven to be optimum for use in demanding evacuation applications. For best results, change vacuum pump oil after each evacuation. Robinair, a Bosch Automotive Service Solutions brand, is a global leader in service tools and equipment based in Owatonna, Minnesota. Robinair is recognized throughout the world as the quality and performance leader in AC/R evacuation tools and this position has led to its success with the full range of products that serve the heating/ventilating/air conditioning/refrigeration (HVAC-R) and mobile markets, which includes the automotive aftermarket along with other industries such as agriculture and construction.