OTC Tools 13204 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 than other leading brands, which means it resists breaking down due to heat for a longer period. 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.