Apiezon H is designed for applications at higher temperatures and of all the Apiezon greases, is the formulation for the highest temperatures. Apiezon H grease can be used over a wide range of temperatures from -10 to + 240° C, while optimum consistency is retained at between +10 and +110° C. There are a growing number of applications for Apiezon H outside of the vacuum area, for example, it is used on a heatsink fan for a computer central processing unit ("CPU"). Apiezon H grease exhibits good vacuum properties (ultimate vapor pressure 1.7x10-10 Torr at 20°C) in the lower to medium vacuum range at higher temperatures, while at lower temperatures, Apiezon H grease can be used in the high vacuum range. Apiezon H is a filled hydrocarbon grease which exhibits excellent heat transfer properties. Allowing heat to conduct away from a site of operation, Apiezon H grease will reduce the danger of overheating and hence will limit the risk of damage to heat sensitive components. Apiezon H grease is manufactured from a unique feedstock containing a high proportion of branched and unsaturated hydrocarbons. These complex structures give Apiezon H grease a very high molecular weight and consequently, strong powers of absorption, particularly for other hydrocarbon molecules. Strong absorption properties ensures that Apiezon H grease has powerful "gettering" action, that is, the power to absorb greasy or chemical impurities on metal and glass surfaces. This is of considerable value in the electronics industry where scrupulous cleanliness of metal surfaces is required.